SQLite

**     COPY
**     VACUUM
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.87 2002/05/08 21:30:15 drh Exp $
** $Id: build.c,v 1.88 2002/05/15 08:30:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called after a single SQL statement has been
** parsed and we want to execute the VDBE code to implement 

    pIndex->isCommit = 1;
  }
  while( (pElem=sqliteHashFirst(&db->idxDrop))!=0 ){
    Index *pIndex = sqliteHashData(pElem);
    sqliteUnlinkAndDeleteIndex(db, pIndex);
  }
  sqliteHashClear(&db->idxDrop);

  /* Set the commit flag on all triggers added this transaction */
  for(pElem=sqliteHashFirst(&db->trigHash); pElem; pElem=sqliteHashNext(pElem)){
    Trigger *pTrigger = sqliteHashData(pElem);
    pTrigger->isCommit = 1;
  }

  /* Delete the structures for triggers removed this transaction */
  pElem = sqliteHashFirst(&db->trigDrop);
  while (pElem) {
    Trigger *pTrigger = sqliteHashData(pElem);
    sqliteDeleteTrigger(pTrigger);
    pElem = sqliteHashNext(pElem);
  }
  sqliteHashClear(&db->trigDrop);

  db->flags &= ~SQLITE_InternChanges;
}

/*
** This routine runs when one or more CREATE TABLE, CREATE INDEX,
** DROP TABLE, or DROP INDEX statements gets rolled back.  The
** additions or deletions of Table and Index structures in the

    Index *pOld, *p = sqliteHashData(pElem);
    assert( p->isCommit );
    p->isDropped = 0;
    pOld = sqliteHashInsert(&db->idxHash, p->zName, strlen(p->zName)+1, p);
    assert( pOld==0 || pOld==p );
  }
  sqliteHashClear(&db->idxDrop);

  /* Remove any triggers that haven't been commited yet */
  for(pElem = sqliteHashFirst(&db->trigHash); pElem; 
      pElem = (pElem?sqliteHashNext(pElem):0)) {
    Trigger * pTrigger = sqliteHashData(pElem);
    if (!pTrigger->isCommit) {
      Table * tbl = sqliteFindTable(db, pTrigger->table);
      if (tbl) {
	if (tbl->pTrigger == pTrigger) 
	  tbl->pTrigger = pTrigger->pNext;
	else {
	  Trigger * cc = tbl->pTrigger;
	  while (cc) {
	    if (cc->pNext == pTrigger) {
	      cc->pNext = cc->pNext->pNext;
	      break;
	    }
	    cc = cc->pNext;
	  }
	  assert(cc);
	}
      }
      sqliteHashInsert(&db->trigHash, pTrigger->name,
	      1 + strlen(pTrigger->name), 0);
      sqliteDeleteTrigger(pTrigger);
      pElem = sqliteHashFirst(&db->trigHash);
    }
  }

  /* Any triggers that were dropped - put 'em back in place */
  for(pElem = sqliteHashFirst(&db->trigDrop); pElem; 
      pElem = sqliteHashNext(pElem)) {
    Trigger * pTrigger = sqliteHashData(pElem);
    Table * tab = sqliteFindTable(db, pTrigger->table);
    sqliteHashInsert(&db->trigHash, pTrigger->name, 
	strlen(pTrigger->name) + 1, pTrigger);

    pTrigger->pNext = tab->pTrigger;
    tab->pTrigger = pTrigger;
  }

  sqliteHashClear(&db->trigDrop);
  db->flags &= ~SQLITE_InternChanges;
}

/*
** Construct the name of a user table or index from a token.
**
** Space to hold the name is obtained from sqliteMalloc() and must

**
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
static void changeCookie(sqlite *db){
void changeCookie(sqlite *db){
  if( db->next_cookie==db->schema_cookie ){
    db->next_cookie = db->schema_cookie + sqliteRandomByte() + 1;
    db->flags |= SQLITE_InternChanges;
  }
}

/*

      { OP_Next,       0, ADDR(4),  0}, /* 8 */
      { OP_Integer,    0, 0,        0}, /* 9 */
      { OP_SetCookie,  0, 0,        0},
      { OP_Close,      0, 0,        0},
    };
    Index *pIdx;
    sqliteBeginWriteOperation(pParse);
    /* Drop all triggers associated with the table being dropped */
    while (pTable->pTrigger) {
      Token tt;
      tt.z = pTable->pTrigger->name;
      tt.n = strlen(pTable->pTrigger->name);
      sqliteDropTrigger(pParse, &tt, 1);
    }
    if( !pTable->isTemp ){
      base = sqliteVdbeAddOpList(v, ArraySize(dropTable), dropTable);
      sqliteVdbeChangeP3(v, base+2, pTable->zName, 0);
      changeCookie(db);
      sqliteVdbeChangeP1(v, base+9, db->next_cookie);
    }
    if( !isView ){

** all.  So there is not need to set a checkpoint is a transaction
** is already in effect.
*/
void sqliteBeginWriteOperation(Parse *pParse){
  Vdbe *v;
  v = sqliteGetVdbe(pParse);
  if( v==0 ) return;
  if (pParse->trigStack) return; /* if this is in a trigger */
  if( (pParse->db->flags & SQLITE_InTrans)==0  ){
    sqliteVdbeAddOp(v, OP_Transaction, 0, 0);
    sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
    pParse->schemaVerified = 1;
  }
}

/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.  The operation might not be atomic in
** the sense that an error may be discovered and the operation might
** abort after some changes have been made.  If we are in the middle 
** of a transaction, then this sets a checkpoint.  If we are not in
** a transaction, then start a transaction.
*/
void sqliteBeginMultiWriteOperation(Parse *pParse){
  Vdbe *v;
  v = sqliteGetVdbe(pParse);
  if( v==0 ) return;
  if (pParse->trigStack) return; /* if this is in a trigger */
  if( (pParse->db->flags & SQLITE_InTrans)==0 ){
    sqliteVdbeAddOp(v, OP_Transaction, 0, 0);
    sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
    pParse->schemaVerified = 1;
  }else{
    sqliteVdbeAddOp(v, OP_Checkpoint, 0, 0);
  }
}

/*
** Generate code that concludes an operation that may have changed
** the database.  This is a companion function to BeginWriteOperation().
** If a transaction was started, then commit it.  If a checkpoint was
** started then commit that.
*/
void sqliteEndWriteOperation(Parse *pParse){
  Vdbe *v;
  if (pParse->trigStack) return; /* if this is in a trigger */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) return;
  if( pParse->db->flags & SQLITE_InTrans ){
    /* Do Nothing */
  }else{
    sqliteVdbeAddOp(v, OP_Commit, 0, 0);
  }

      int size = db->cache_size;
      if( size<0 ) size = -size;
      if( !getBoolean(zRight) ) size = -size;
      db->cache_size = size;
      sqliteBtreeSetCacheSize(db->pBe, db->cache_size);
    }
  }else

  if( sqliteStrICmp(zLeft, "trigger_overhead_test")==0 ){
    if( getBoolean(zRight) ){
      always_code_trigger_setup = 1;
    }else{
      always_code_trigger_setup = 0;
    }
  }else

  if( sqliteStrICmp(zLeft, "vdbe_trace")==0 ){
    if( getBoolean(zRight) ){
      db->flags |= SQLITE_VdbeTrace;
    }else{
      db->flags &= ~SQLITE_VdbeTrace;
    }

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
** $Id: delete.c,v 1.30 2002/04/12 10:08:59 drh Exp $
** $Id: delete.c,v 1.31 2002/05/15 08:30:13 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Given a table name, find the corresponding table and make sure the
** table is writeable.  Generate an error and return NULL if not.  If

  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */
  int base;              /* Index of the first available table cursor */
  sqlite *db;            /* Main database structure */
  int openOp;            /* Opcode used to open a cursor to the table */

  int row_triggers_exist = 0;
  int oldIdx = -1;

  if( pParse->nErr || sqlite_malloc_failed ){
    pTabList = 0;
    goto delete_from_cleanup;
  }
  db = pParse->db;

  /* Check for the special case of a VIEW with one or more ON DELETE triggers 
   * defined 
   */
  {
    Table * pTab;
    char * zTab = sqliteTableNameFromToken(pTableName);

    if(zTab != 0) {
      pTab = sqliteFindTable(pParse->db, zTab);
      if (pTab) {
	row_triggers_exist = 
	  sqliteTriggersExist(pParse, pTab->pTrigger, 
	      TK_DELETE, TK_BEFORE, TK_ROW, 0) ||
	  sqliteTriggersExist(pParse, pTab->pTrigger, 
	      TK_DELETE, TK_AFTER, TK_ROW, 0);
      }
      sqliteFree(zTab);
      if (row_triggers_exist &&  pTab->pSelect ) {
	/* Just fire VIEW triggers */
	sqliteViewTriggers(pParse, pTab, pWhere, OE_Replace, 0);
	return;
      }
    }
  }

  /* Locate the table which we want to delete.  This table has to be
  ** put in an IdList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect
  ** an IdList* parameter instead of just a Table* parameger.
  */
  pTabList = sqliteTableTokenToIdList(pParse, pTableName);
  if( pTabList==0 ) goto delete_from_cleanup;
  assert( pTabList->nId==1 );
  pTab = pTabList->a[0].pTab;
  assert( pTab->pSelect==0 );  /* This table is not a view */

  if (row_triggers_exist) 
    oldIdx = pParse->nTab++;

  /* Resolve the column names in all the expressions.
  */
  base = pParse->nTab++;
  if( pWhere ){
    if( sqliteExprResolveIds(pParse, base, pTabList, 0, pWhere) ){
      goto delete_from_cleanup;
    }
    if( sqliteExprCheck(pParse, pWhere, 0, 0) ){
      goto delete_from_cleanup;
    }
  }

  /* Begin generating code.
  */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto delete_from_cleanup;
  if (row_triggers_exist) 
    sqliteBeginMultiWriteOperation(pParse);
  else 
  sqliteBeginWriteOperation(pParse);
    sqliteBeginWriteOperation(pParse);

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
    sqliteVdbeAddOp(v, OP_Integer, 0, 0);
  }

  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.
  */
  if( pWhere==0 ){
  if( pWhere==0 && !row_triggers_exist){
    if( db->flags & SQLITE_CountRows ){
      /* If counting rows deleted, just count the total number of
      ** entries in the table. */
      int endOfLoop = sqliteVdbeMakeLabel(v);
      int addr;
      openOp = pTab->isTemp ? OP_OpenAux : OP_Open;
      assert( base==0 );

    sqliteWhereEnd(pWInfo);

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
    end = sqliteVdbeMakeLabel(v);

    if (row_triggers_exist) {
      int ii;
      addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
      sqliteVdbeAddOp(v, OP_Dup, 0, 0);

      openOp = pTab->isTemp ? OP_OpenAux : OP_Open;
      sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
      sqliteVdbeAddOp(v, OP_MoveTo, base, 0);
      sqliteVdbeAddOp(v, OP_OpenTemp, oldIdx, 0);

      sqliteVdbeAddOp(v, OP_Integer, 13, 0);
      for (ii = 0; ii < pTab->nCol; ii++) {
	if (ii == pTab->iPKey) 
	  sqliteVdbeAddOp(v, OP_Recno, base, 0);
	else
	  sqliteVdbeAddOp(v, OP_Column, base, ii);
      }
      sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
      sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      sqliteVdbeAddOp(v, OP_Rewind, oldIdx, 0);

      sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1, 
	  oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
    }

    pParse->nTab = base + 1;
    openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
    sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
    for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
      sqliteVdbeAddOp(v, openOp, base+i, pIdx->tnum);
      sqliteVdbeAddOp(v, openOp, pParse->nTab++, pIdx->tnum);
    }
    end = sqliteVdbeMakeLabel(v);
    addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);
    sqliteGenerateRowDelete(v, pTab, base, 1);

    if (!row_triggers_exist) 
      addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end);

    sqliteGenerateRowDelete(v, pTab, base, pParse->trigStack?0:1);

    if (row_triggers_exist) {
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
	sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
      }
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1, 
	  oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default);
    }

    sqliteVdbeAddOp(v, OP_Goto, 0, addr);
    sqliteVdbeResolveLabel(v, end);
    sqliteVdbeAddOp(v, OP_ListReset, 0, 0);

    if (!row_triggers_exist) {
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
	sqliteVdbeAddOp(v, OP_Close, base + i, pIdx->tnum);
      }
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      pParse->nTab = base;
    }
  }
  sqliteEndWriteOperation(pParse);

  /*
  ** Return the number of rows that were deleted.
  */
  if( db->flags & SQLITE_CountRows ){

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.58 2002/04/20 14:24:42 drh Exp $
** $Id: expr.c,v 1.59 2002/05/15 08:30:13 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function

              pExpr->iColumn = -1;
            }else{
              pExpr->iColumn = j;
            }
          }
        }
      }

      /* If we have not already resolved this *.* expression, then maybe 
       * it is a new.* or old.* trigger argument reference */
      if (cnt == 0 && pParse->trigStack != 0) {
        TriggerStack * tt = pParse->trigStack;
        int j;
        int t = 0;
        if (tt->newIdx != -1 && sqliteStrICmp("new", zLeft) == 0) {
          pExpr->iTable = tt->newIdx;
          cntTab++;
          t = 1;
        }
        if (tt->oldIdx != -1 && sqliteStrICmp("old", zLeft) == 0) {
          pExpr->iTable = tt->oldIdx;
          cntTab++;
          t = 1;
        }

        if (t) 
          for(j=0; j<tt->pTab->nCol; j++) {
            if( sqliteStrICmp(tt->pTab->aCol[j].zName, zRight)==0 ){
              cnt++;
              pExpr->iColumn = j;
            }
          }
      }

      if( cnt==0 && cntTab==1 && sqliteIsRowid(zRight) ){
        cnt = 1;
        pExpr->iColumn = -1;
      }
      sqliteFree(zLeft);
      sqliteFree(zRight);
      if( cnt==0 ){

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.52 2002/04/12 10:08:59 drh Exp $
** $Id: insert.c,v 1.53 2002/05/15 08:30:13 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)

  Token *pTableName,    /* Name of table into which we are inserting */
  ExprList *pList,      /* List of values to be inserted */
  Select *pSelect,      /* A SELECT statement to use as the data source */
  IdList *pColumn,      /* Column names corresponding to IDLIST. */
  int onError           /* How to handle constraint errors */
){
  Table *pTab;          /* The table to insert into */
  char *zTab;           /* Name of the table into which we are inserting */
  char *zTab = 0;       /* Name of the table into which we are inserting */
  int i, j, idx;        /* Loop counters */
  Vdbe *v;              /* Generate code into this virtual machine */
  Index *pIdx;          /* For looping over indices of the table */
  int srcTab;           /* Date comes from this temporary cursor if >=0 */
  int nColumn;          /* Number of columns in the data */
  int base;             /* First available cursor */
  int iCont, iBreak;    /* Beginning and end of the loop over srcTab */
  sqlite *db;           /* The main database structure */
  int openOp;           /* Opcode used to open cursors */
  int keyColumn = -1;   /* Column that is the INTEGER PRIMARY KEY */
  int endOfLoop;        /* Label for the end of the insertion loop */

  int row_triggers_exist = 0; /* True if there are FOR EACH ROW triggers */
  int newIdx = -1;

  if( pParse->nErr || sqlite_malloc_failed ) goto insert_cleanup;
  db = pParse->db;

  /* Locate the table into which we will be inserting new information.
  */
  zTab = sqliteTableNameFromToken(pTableName);
  if( zTab==0 ) goto insert_cleanup;
  pTab = sqliteFindTable(pParse->db, zTab);
  if( pTab==0 ){
    sqliteSetString(&pParse->zErrMsg, "no such table: ", zTab, 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  pTab = sqliteTableNameToTable(pParse, zTab);

  /* Ensure that:
  *  (a) the table is not read-only, 
  *  (b) that if it is a view then ON INSERT triggers exist
  */
  row_triggers_exist = 
    sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT, 
	TK_BEFORE, TK_ROW, 0) ||
    sqliteTriggersExist(pParse, pTab->pTrigger, TK_INSERT, TK_AFTER, TK_ROW, 0);
  if( pTab->readOnly || (pTab->pSelect && !row_triggers_exist) ){
    sqliteSetString(&pParse->zErrMsg, 
      pTab->pSelect ? "view " : "table ",
      zTab,
      " may not be modified", 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  sqliteFree(zTab);
  zTab = 0;

  if( pTab==0 ) goto insert_cleanup;
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */

  /* Allocate a VDBE
  */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pSelect ){
  if( pSelect || row_triggers_exist ){
    sqliteBeginMultiWriteOperation(pParse);
  }else{
    sqliteBeginWriteOperation(pParse);
  }

  /* if there are row triggers, allocate a temp table for new.* references. */
  if (row_triggers_exist)
    newIdx = pParse->nTab++;

  /* Figure out how many columns of data are supplied.  If the data
  ** is coming from a SELECT statement, then this step has to generate
  ** all the code to implement the SELECT statement and leave the data
  ** in a temporary table.  If data is coming from an expression list,
  ** then we just have to count the number of expressions.
  */

  ** key, the set the keyColumn variable to the primary key column index
  ** in the original table definition.
  */
  if( pColumn==0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open cursors into the table that is received the new data and
  ** all indices of that table.
  /* Open the temp table for FOR EACH ROW triggers */
  if (row_triggers_exist)
    sqliteVdbeAddOp(v, OP_OpenTemp, newIdx, 0);
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqliteVdbeAddOp(v, OP_Integer, 0, 0);  /* Initialize the row count */
  }

  /* Open tables and indices if there are no row triggers */
  if (!row_triggers_exist) {
  base = pParse->nTab;
  openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
  sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
  sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
  for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
    sqliteVdbeAddOp(v, openOp, idx+base, pIdx->tnum);
    sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
  }
  pParse->nTab += idx;

    base = pParse->nTab;
    openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
    sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
    sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqliteVdbeAddOp(v, openOp, idx+base, pIdx->tnum);
      sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
    }
    pParse->nTab += idx;
  }
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    sqliteVdbeAddOp(v, OP_Integer, 0, 0);  /* Initialize the row count */
  }

  /* If the data source is a SELECT statement, then we have to create
  ** a loop because there might be multiple rows of data.  If the data
  ** source is an expression list, then exactly one row will be inserted
  ** and the loop is not used.
  */
  if( srcTab>=0 ){
    iBreak = sqliteVdbeMakeLabel(v);
    sqliteVdbeAddOp(v, OP_Rewind, srcTab, iBreak);
    iCont = sqliteVdbeCurrentAddr(v);
  }

  if (row_triggers_exist) {

    /* build the new.* reference row */
    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for(i=0; i<pTab->nCol; i++){
      if( pColumn==0 ){
	j = i;
      }else{
	for(j=0; j<pColumn->nId; j++){
	  if( pColumn->a[j].idx==i ) break;
	}
      }
      if( pColumn && j>=pColumn->nId ){
	sqliteVdbeAddOp(v, OP_String, 0, 0);
	sqliteVdbeChangeP3(v, -1, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( srcTab>=0 ){
	sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else{
	sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    /* Fire BEFORE triggers */
    if (
    sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_BEFORE, pTab, newIdx, -1, 
	onError)
       ) goto insert_cleanup;

    /* Open the tables and indices for the INSERT */
    if (!pTab->pSelect) {
      base = pParse->nTab;
      openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
      sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
      sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
      for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
	sqliteVdbeAddOp(v, openOp, idx+base, pIdx->tnum);
	sqliteVdbeChangeP3(v, -1, pIdx->zName, P3_STATIC);
      }
      pParse->nTab += idx;
    }
  }

  /* Push the record number for the new entry onto the stack.  The
  ** record number is a randomly generate integer created by NewRecno
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */
  if (!pTab->pSelect) {
  if( keyColumn>=0 ){
    if( srcTab>=0 ){
      sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
    }else{
      int addr;
      sqliteExprCode(pParse, pList->a[keyColumn].pExpr);
    if( keyColumn>=0 ){
      if( srcTab>=0 ){
	sqliteVdbeAddOp(v, OP_Column, srcTab, keyColumn);
      }else{
	int addr;
	sqliteExprCode(pParse, pList->a[keyColumn].pExpr);

      /* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
      ** to generate a unique primary key value.
      */
      addr = sqliteVdbeAddOp(v, OP_Dup, 0, 1);
      sqliteVdbeAddOp(v, OP_NotNull, 0, addr+4);
      sqliteVdbeAddOp(v, OP_Pop, 1, 0);
      sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
    }
    sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
  }else{
    sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
  }
	/* If the PRIMARY KEY expression is NULL, then use OP_NewRecno
	 ** to generate a unique primary key value.
	 */
	addr = sqliteVdbeAddOp(v, OP_Dup, 0, 1);
	sqliteVdbeAddOp(v, OP_NotNull, 0, addr+4);
	sqliteVdbeAddOp(v, OP_Pop, 1, 0);
	sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
      }
      sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);
    }else{
      sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
    }

  /* Push onto the stack, data for all columns of the new entry, beginning
  ** with the first column.
  */
  for(i=0; i<pTab->nCol; i++){
    if( i==pTab->iPKey ){
      /* The value of the INTEGER PRIMARY KEY column is always a NULL.
      ** Whenever this column is read, the record number will be substituted
      ** in its place.  So will fill this column with a NULL to avoid
      ** taking up data space with information that will never be used. */
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      continue;
    }
    if( pColumn==0 ){
      j = i;
    }else{
      for(j=0; j<pColumn->nId; j++){
        if( pColumn->a[j].idx==i ) break;
      }
    }
    if( pColumn && j>=pColumn->nId ){
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      sqliteVdbeChangeP3(v, -1, pTab->aCol[i].zDflt, P3_STATIC);
    }else if( srcTab>=0 ){
      sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
    }else{
      sqliteExprCode(pParse, pList->a[j].pExpr);
    }
  }
    /* Push onto the stack, data for all columns of the new entry, beginning
     ** with the first column.
     */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
	/* The value of the INTEGER PRIMARY KEY column is always a NULL.
	 ** Whenever this column is read, the record number will be substituted
	 ** in its place.  So will fill this column with a NULL to avoid
	 ** taking up data space with information that will never be used. */
	sqliteVdbeAddOp(v, OP_String, 0, 0);
	continue;
      }
      if( pColumn==0 ){
	j = i;
      }else{
	for(j=0; j<pColumn->nId; j++){
	  if( pColumn->a[j].idx==i ) break;
	}
      }
      if( pColumn && j>=pColumn->nId ){
	sqliteVdbeAddOp(v, OP_String, 0, 0);
	sqliteVdbeChangeP3(v, -1, pTab->aCol[i].zDflt, P3_STATIC);
      }else if( srcTab>=0 ){
	sqliteVdbeAddOp(v, OP_Column, srcTab, j); 
      }else{
	sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }

  /* Generate code to check constraints and generate index keys and
  ** do the insertion.
  */
  endOfLoop = sqliteVdbeMakeLabel(v);
  sqliteGenerateConstraintChecks(pParse, pTab, base, 0,0,0, onError, endOfLoop);
  sqliteCompleteInsertion(pParse, pTab, base, 0,0,0);
    /* Generate code to check constraints and generate index keys and
     ** do the insertion.
     */
    endOfLoop = sqliteVdbeMakeLabel(v);
    sqliteGenerateConstraintChecks(pParse, pTab, base, 0,0,0,onError,endOfLoop);
    sqliteCompleteInsertion(pParse, pTab, base, 0,0,0);

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
    /* Update the count of rows that are inserted
     */
    if( (db->flags & SQLITE_CountRows)!=0 && !pParse->trigStack){
      sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
    }
  }

  if (row_triggers_exist) {
    /* Close all tables opened */
    if (!pTab->pSelect) {
      sqliteVdbeAddOp(v, OP_Close, base, 0);
      for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
	sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
      }
    }

    /* Code AFTER triggers */
    if (
	sqliteCodeRowTrigger(pParse, TK_INSERT, 0, TK_AFTER, pTab, newIdx, -1, 
	  onError)
       ) goto insert_cleanup;
  }

  /* The bottom of the loop, if the data source is a SELECT statement
  */
   */
  sqliteVdbeResolveLabel(v, endOfLoop);
  if( srcTab>=0 ){
    sqliteVdbeAddOp(v, OP_Next, srcTab, iCont);
    sqliteVdbeResolveLabel(v, iBreak);
    sqliteVdbeAddOp(v, OP_Close, srcTab, 0);
  }

  if (!row_triggers_exist) {
    /* Close all tables opened */
  sqliteVdbeAddOp(v, OP_Close, base, 0);
  for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
    sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
  }
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqliteVdbeAddOp(v, OP_Close, idx+base, 0);
    }
  }

  sqliteEndWriteOperation(pParse);

  /*
  ** Return the number of rows inserted.
   ** Return the number of rows inserted.
  */
  if( db->flags & SQLITE_CountRows ){
  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
    sqliteVdbeAddOp(v, OP_ColumnCount, 1, 0);
    sqliteVdbeAddOp(v, OP_ColumnName, 0, 0);
    sqliteVdbeChangeP3(v, -1, "rows inserted", P3_STATIC);
    sqliteVdbeAddOp(v, OP_Callback, 1, 0);
  }

insert_cleanup:
  if( pList ) sqliteExprListDelete(pList);
  if( pSelect ) sqliteSelectDelete(pSelect);
  if ( zTab ) sqliteFree(zTab);
  sqliteIdListDelete(pColumn);
}

/*
** Generate code to do a constraint check prior to an INSERT or an UPDATE.
**
** When this routine is called, the stack contains (from bottom to top)

  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aIdxUsed && aIdxUsed[i]==0 ) continue;
    sqliteVdbeAddOp(v, OP_IdxPut, base+i+1, 0);
  }
  sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
  sqliteVdbeAddOp(v, OP_PutIntKey, base, 1);
  sqliteVdbeAddOp(v, OP_PutIntKey, base, pParse->trigStack?0:1);
  if( isUpdate && recnoChng ){
    sqliteVdbeAddOp(v, OP_Pop, 1, 0);
  }
}

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.71 2002/05/10 13:14:07 drh Exp $
** $Id: main.c,v 1.72 2002/05/15 08:30:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"

/*
** This is the callback routine for the code that initializes the
** database.  See sqliteInit() below for additional information.

  /* Allocate the sqlite data structure */
  db = sqliteMalloc( sizeof(sqlite) );
  if( pzErrMsg ) *pzErrMsg = 0;
  if( db==0 ) goto no_mem_on_open;
  sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->idxHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->trigHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->trigDrop, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->tblDrop, SQLITE_HASH_POINTER, 0);
  sqliteHashInit(&db->idxDrop, SQLITE_HASH_POINTER, 0);
  sqliteHashInit(&db->aFunc, SQLITE_HASH_STRING, 1);
  sqliteRegisterBuildinFunctions(db);
  db->onError = OE_Default;
  db->priorNewRowid = 0;
  db->magic = SQLITE_MAGIC_BUSY;

** This routine erases the stored schema.  This erasure occurs because
** either the database is being closed or because some other process
** changed the schema and this process needs to reread it.
*/
static void clearHashTable(sqlite *db, int preserveTemps){
  HashElem *pElem;
  Hash temp1;
  Hash temp2;
  assert( sqliteHashFirst(&db->tblDrop)==0 ); /* There can not be uncommitted */
  assert( sqliteHashFirst(&db->idxDrop)==0 ); /*   DROP TABLEs or DROP INDEXs */
  temp1 = db->tblHash;
  temp2 = db->trigHash;
  sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->trigHash, SQLITE_HASH_STRING, 0);
  sqliteHashClear(&db->idxHash);

  for (pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
    Trigger * pTrigger = sqliteHashData(pElem);
    Table *pTab = sqliteFindTable(db, pTrigger->table);
    assert(pTab);
    if (pTab->isTemp) { 
      sqliteHashInsert(&db->trigHash, pTrigger->name, strlen(pTrigger->name), 
	  pTrigger);
    } else {
      sqliteDeleteTrigger(pTrigger);
    }
  }
  sqliteHashClear(&temp2);

  sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);

  for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    if( preserveTemps && pTab->isTemp ){
      Index *pIdx;
      int nName = strlen(pTab->zName);
      Table *pOld = sqliteHashInsert(&db->tblHash, pTab->zName, nName+1, pTab);
      if( pOld!=0 ){

        }
      }
    }else{
      sqliteDeleteTable(db, pTab);
    }
  }
  sqliteHashClear(&temp1);

  db->flags &= ~SQLITE_Initialized;
}

/*
** Return the ROWID of the most recent insert
*/
int sqlite_last_insert_rowid(sqlite *db){

}

/*
** Return TRUE if the given SQL string ends in a semicolon.
*/
int sqlite_complete(const char *zSql){
  int isComplete = 0;
  int seenCreate = 0;
  while( *zSql ){
    switch( *zSql ){
      case ';': {
        isComplete = 1;
        break;
      }
      case ' ':

          break;
        }
        while( *zSql && *zSql!='\n' ){ zSql++; }
        if( *zSql==0 ) return isComplete;
        break;
      } 
      default: {
        if (seenCreate && !sqliteStrNICmp(zSql, "trigger", 7)) 
	  while (sqliteStrNICmp(zSql, "end", 3))
	    if (!*++zSql) return 0;

        if (!sqliteStrNICmp(zSql, "create", 6)) {
	  zSql = zSql + 5;
	  seenCreate = 1;
	} else 
	  seenCreate = 0;

        isComplete = 0;
        break;
      }
    }
    zSql++;
  }
  return isComplete;

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.63 2002/05/08 21:46:15 drh Exp $
** @(#) $Id: parse.y,v 1.64 2002/05/15 08:30:14 danielk1977 Exp $
*/
%token_prefix TK_
%token_type {Token}
%default_type {Token}
%extra_argument {Parse *pParse}
%syntax_error {
  sqliteSetString(&pParse->zErrMsg,"syntax error",0);
  pParse->sErrToken = TOKEN;
}
%name sqliteParser
%include {
#include "sqliteInt.h"
#include "parse.h"

/*
** A structure for holding two integers
*/
struct twoint { int a,b; };

/*
** A structure for holding an integer and an IdList
*/
struct int_idlist { int a; IdList * b; };
}

// These are extra tokens used by the lexer but never seen by the
// parser.  We put them in a rule so that the parser generator will
// add them to the parse.h output file.
//
%nonassoc END_OF_FILE ILLEGAL SPACE UNCLOSED_STRING COMMENT FUNCTION

cmd ::= PRAGMA ids(X).                   {sqlitePragma(pParse,&X,&X,0);}
plus_num(A) ::= plus_opt number(X).   {A = X;}
minus_num(A) ::= MINUS number(X).     {A = X;}
number(A) ::= INTEGER(X).  {A = X;}
number(A) ::= FLOAT(X).    {A = X;}
plus_opt ::= PLUS.
plus_opt ::= .

//////////////////////////// The CREATE TRIGGER command /////////////////////
cmd ::= CREATE(A) TRIGGER ids(B) trigger_time(C) trigger_event(D) ON ids(E) 
                  foreach_clause(F) when_clause(G)
                  BEGIN trigger_cmd_list(S) END(Z). {
  sqliteCreateTrigger(pParse, &B, C, D.a, D.b, &E, F, G, S, 
      A.z, (int)(Z.z - A.z) + Z.n );
}

%type trigger_time  {int}
trigger_time(A) ::= BEFORE.      { A = TK_BEFORE; }
trigger_time(A) ::= AFTER.       { A = TK_AFTER;  }
trigger_time(A) ::= INSTEAD OF.  { A = TK_INSTEAD;}
trigger_time(A) ::= .            { A = TK_BEFORE; }

%type trigger_event {struct int_idlist}
trigger_event(A) ::= DELETE. { A.a = TK_DELETE; A.b = 0; }
trigger_event(A) ::= INSERT. { A.a = TK_INSERT; A.b = 0; }
trigger_event(A) ::= UPDATE. { A.a = TK_UPDATE; A.b = 0;}
trigger_event(A) ::= UPDATE OF inscollist(X). {A.a = TK_UPDATE; A.b = X; }

%type foreach_clause {int}
foreach_clause(A) ::= .                   { A = TK_ROW; }
foreach_clause(A) ::= FOR EACH ROW.       { A = TK_ROW; }
foreach_clause(A) ::= FOR EACH STATEMENT. { A = TK_STATEMENT; }

%type when_clause {Expr *}
when_clause(A) ::= .             { A = 0; }
when_clause(A) ::= WHEN expr(X). { A = X; }

%type trigger_cmd_list {TriggerStep *}
trigger_cmd_list(A) ::= trigger_cmd(X) SEMI trigger_cmd_list(Y). {
  X->pNext = Y ; A = X; }
trigger_cmd_list(A) ::= . { A = 0; }

%type trigger_cmd {TriggerStep *}
// UPDATE 
trigger_cmd(A) ::= UPDATE orconf(R) ids(X) SET setlist(Y) where_opt(Z).  
               { A = sqliteTriggerUpdateStep(&X, Y, Z, R); }

// INSERT
trigger_cmd(A) ::= INSERT orconf(R) INTO ids(X) inscollist_opt(F) 
  VALUES LP itemlist(Y) RP.  
{A = sqliteTriggerInsertStep(&X, F, Y, 0, R);}

trigger_cmd(A) ::= INSERT orconf(R) INTO ids(X) inscollist_opt(F) select(S).
               {A = sqliteTriggerInsertStep(&X, F, 0, S, R);}

// DELETE
trigger_cmd(A) ::= DELETE FROM ids(X) where_opt(Y).
               {A = sqliteTriggerDeleteStep(&X, Y);}

// SELECT
trigger_cmd(A) ::= select(X).  {A = sqliteTriggerSelectStep(X); }

////////////////////////  DROP TRIGGER statement //////////////////////////////
cmd ::= DROP TRIGGER ids(X). {
    sqliteDropTrigger(pParse,&X,0);
}

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.107 2002/05/10 13:14:07 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.108 2002/05/15 08:30:14 danielk1977 Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>

typedef struct Token Token;
typedef struct IdList IdList;
typedef struct WhereInfo WhereInfo;
typedef struct WhereLevel WhereLevel;
typedef struct Select Select;
typedef struct AggExpr AggExpr;
typedef struct FuncDef FuncDef;
typedef struct Trigger Trigger;
typedef struct TriggerStep TriggerStep;
typedef struct TriggerStack TriggerStack;

/*
** Each database is an instance of the following structure
*/
struct sqlite {
  Btree *pBe;                   /* The B*Tree backend */
  Btree *pBeTemp;               /* Backend for session temporary tables */

  Hash aFunc;                   /* All functions that can be in SQL exprs */
  int lastRowid;                /* ROWID of most recent insert */
  int priorNewRowid;            /* Last randomly generated ROWID */
  int onError;                  /* Default conflict algorithm */
  int magic;                    /* Magic number for detect library misuse */
  int nChange;                  /* Number of rows changed */
  int recursionDepth;           /* Number of nested calls to sqlite_exec() */

  Hash trigHash;                /* All triggers indexed by name */
  Hash trigDrop;                /* Uncommited dropped triggers */
};

/*
** Possible values for the sqlite.flags.
*/
#define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
#define SQLITE_Initialized    0x00000002  /* True after initialization */

  Select *pSelect; /* NULL for tables.  Points to definition if a view. */
  u8 readOnly;     /* True if this table should not be written by the user */
  u8 isCommit;     /* True if creation of this table has been committed */
  u8 isTemp;       /* True if stored in db->pBeTemp instead of db->pBe */
  u8 isTransient;  /* True if automatically deleted when VDBE finishes */
  u8 hasPrimKey;   /* True if there exists a primary key */
  u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */

  Trigger *pTrigger; /* List of SQL triggers on this table */
};

/*
** SQLite supports 5 different ways to resolve a contraint
** error.  ROLLBACK processing means that a constraint violation
** causes the operation in proces to fail and for the current transaction
** to be rolled back.  ABORT processing means the operation in process

  int nSet;            /* Number of sets used so far */
  int nAgg;            /* Number of aggregate expressions */
  AggExpr *aAgg;       /* An array of aggregate expressions */
  int useAgg;          /* If true, extract field values from the aggregator
                       ** while generating expressions.  Normally false */
  int schemaVerified;  /* True if an OP_VerifySchema has been coded someplace
                       ** other than after an OP_Transaction */

  TriggerStack * trigStack;
};

struct TriggerStack {
  Trigger * pTrigger;
  Table *   pTab;         /* Table that triggers are currently being coded as */
  int       newIdx;       /* Index of "new" temp table */
  int       oldIdx;       /* Index of "old" temp table */
  int       orconf;       /* Current orconf policy */
  struct TriggerStack * pNext;
};
struct TriggerStep {
  int op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
  int orconf;

  Select * pSelect;     /* Valid for SELECT and sometimes 
			   INSERT steps (when pExprList == 0) */
  Token target;         /* Valid for DELETE, UPDATE, INSERT steps */
  Expr * pWhere;        /* Valid for DELETE, UPDATE steps */
  ExprList * pExprList; /* Valid for UPDATE statements and sometimes 
			   INSERT steps (when pSelect == 0)         */
  IdList *pIdList;      /* Valid for INSERT statements only */

  TriggerStep * pNext;  /* Next in the link-list */
};
struct Trigger {
  char * name;             /* The name of the trigger                        */
  char * table;            /* The table or view to which the trigger applies */
  int    op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
  int    tr_tm;            /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD         */
  Expr * pWhen;            /* The WHEN clause of the expresion (may be NULL) */
  IdList * pColumns;       /* If this is an UPDATE OF <column-list> trigger,
			      the column names are stored in this list       */
  int foreach;             /* One of TK_ROW or TK_STATEMENT */

  TriggerStep * step_list; /* Link list of trigger program steps             */

  char * strings;  /* pointer to the allocation of Token strings */
  Trigger * pNext; /* Next trigger associated with the table */
  int isCommit;
};

TriggerStep * sqliteTriggerSelectStep(Select *);
TriggerStep * sqliteTriggerInsertStep(Token *, IdList *, ExprList *, 
    Select *, int);
TriggerStep * sqliteTriggerUpdateStep(Token *, ExprList *, Expr *, int);
TriggerStep * sqliteTriggerDeleteStep(Token *, Expr *);

extern int always_code_trigger_setup;

void sqliteCreateTrigger(Parse * ,Token *, int, int, IdList *, Token *, int, Expr *, TriggerStep *, char const *,int);
void sqliteDropTrigger(Parse *, Token *, int);
int sqliteTriggersExist( Parse * , Trigger * , int , int , int, ExprList * );
int sqliteCodeRowTrigger( Parse * pParse, int op, ExprList *, int tr_tm,   Table * tbl, int newTable, int oldTable, int onError);

void sqliteViewTriggers(Parse *, Table *, Expr *, int, ExprList *);

/*
** Internal function prototypes
*/
int sqliteStrICmp(const char *, const char *);
int sqliteStrNICmp(const char *, const char *, int);
int sqliteHashNoCase(const char *, int);
int sqliteCompare(const char *, const char *);

IdList *sqliteIdListDup(IdList*);
Select *sqliteSelectDup(Select*);
FuncDef *sqliteFindFunction(sqlite*,const char*,int,int,int);
void sqliteRegisterBuildinFunctions(sqlite*);
int sqliteSafetyOn(sqlite*);
int sqliteSafetyOff(sqlite*);
int sqliteSafetyCheck(sqlite*);

void changeCookie(sqlite *);

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.40 2002/03/24 13:13:29 drh Exp $
** $Id: tokenize.c,v 1.41 2002/05/15 08:30:14 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*

};

/*
** These are the keywords
*/
static Keyword aKeywordTable[] = {
  { "ABORT",             0, TK_ABORT,            0 },
  { "AFTER",             0, TK_AFTER,            0 },
  { "ALL",               0, TK_ALL,              0 },
  { "AND",               0, TK_AND,              0 },
  { "AS",                0, TK_AS,               0 },
  { "ASC",               0, TK_ASC,              0 },
  { "BEFORE",            0, TK_BEFORE,           0 },
  { "BEGIN",             0, TK_BEGIN,            0 },
  { "BETWEEN",           0, TK_BETWEEN,          0 },
  { "BY",                0, TK_BY,               0 },
  { "CASE",              0, TK_CASE,             0 },
  { "CHECK",             0, TK_CHECK,            0 },
  { "CLUSTER",           0, TK_CLUSTER,          0 },
  { "COMMIT",            0, TK_COMMIT,           0 },
  { "CONFLICT",          0, TK_CONFLICT,         0 },
  { "CONSTRAINT",        0, TK_CONSTRAINT,       0 },
  { "COPY",              0, TK_COPY,             0 },
  { "CREATE",            0, TK_CREATE,           0 },
  { "DEFAULT",           0, TK_DEFAULT,          0 },
  { "DELETE",            0, TK_DELETE,           0 },
  { "DELIMITERS",        0, TK_DELIMITERS,       0 },
  { "DESC",              0, TK_DESC,             0 },
  { "DISTINCT",          0, TK_DISTINCT,         0 },
  { "DROP",              0, TK_DROP,             0 },
  { "END",               0, TK_END,              0 },
  { "EACH",              0, TK_EACH,             0 },
  { "ELSE",              0, TK_ELSE,             0 },
  { "EXCEPT",            0, TK_EXCEPT,           0 },
  { "EXPLAIN",           0, TK_EXPLAIN,          0 },
  { "FAIL",              0, TK_FAIL,             0 },
  { "FOR",               0, TK_FOR,              0 },
  { "FROM",              0, TK_FROM,             0 },
  { "GLOB",              0, TK_GLOB,             0 },
  { "GROUP",             0, TK_GROUP,            0 },
  { "HAVING",            0, TK_HAVING,           0 },
  { "IGNORE",            0, TK_IGNORE,           0 },
  { "IN",                0, TK_IN,               0 },
  { "INDEX",             0, TK_INDEX,            0 },
  { "INSERT",            0, TK_INSERT,           0 },
  { "INSTEAD",           0, TK_INSTEAD,          0 },
  { "INTERSECT",         0, TK_INTERSECT,        0 },
  { "INTO",              0, TK_INTO,             0 },
  { "IS",                0, TK_IS,               0 },
  { "ISNULL",            0, TK_ISNULL,           0 },
  { "KEY",               0, TK_KEY,              0 },
  { "LIKE",              0, TK_LIKE,             0 },
  { "LIMIT",             0, TK_LIMIT,            0 },
  { "NOT",               0, TK_NOT,              0 },
  { "NOTNULL",           0, TK_NOTNULL,          0 },
  { "NULL",              0, TK_NULL,             0 },
  { "OF",                0, TK_OF,               0 },
  { "OFFSET",            0, TK_OFFSET,           0 },
  { "ON",                0, TK_ON,               0 },
  { "OR",                0, TK_OR,               0 },
  { "ORDER",             0, TK_ORDER,            0 },
  { "PRAGMA",            0, TK_PRAGMA,           0 },
  { "PRIMARY",           0, TK_PRIMARY,          0 },
  { "REPLACE",           0, TK_REPLACE,          0 },
  { "ROLLBACK",          0, TK_ROLLBACK,         0 },
  { "ROW",               0, TK_ROW,              0 },
  { "SELECT",            0, TK_SELECT,           0 },
  { "SET",               0, TK_SET,              0 },
  { "TABLE",             0, TK_TABLE,            0 },
  { "TEMP",              0, TK_TEMP,             0 },
  { "TEMPORARY",         0, TK_TEMP,             0 },
  { "THEN",              0, TK_THEN,             0 },
  { "TRANSACTION",       0, TK_TRANSACTION,      0 },
  { "TRIGGER",           0, TK_TRIGGER,          0 },
  { "UNION",             0, TK_UNION,            0 },
  { "UNIQUE",            0, TK_UNIQUE,           0 },
  { "UPDATE",            0, TK_UPDATE,           0 },
  { "USING",             0, TK_USING,            0 },
  { "VACUUM",            0, TK_VACUUM,           0 },
  { "VALUES",            0, TK_VALUES,           0 },
  { "VIEW",              0, TK_VIEW,             0 },

/*
 * All copyright on this work is disclaimed by the author.
 *
 */

#include "sqliteInt.h"
/*
 * This is called by the parser when it sees a CREATE TRIGGER statement
 */
void 
sqliteCreateTrigger(
    Parse * pParse, /* The parse context of the CREATE TRIGGER statement */
    Token * nm,     /* The name of the trigger */
    int tr_tm,      /* One of TK_BEFORE, TK_AFTER */
    int op,         /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
    IdList * cols,  /* column list if this is an UPDATE OF trigger */
    Token * tbl,    /* The name of the table/view the trigger applies to */
    int foreach,    /* One of TK_ROW or TK_STATEMENT */
    Expr * pWhen,   /* WHEN clause */
    TriggerStep * steps,      /* The triggered program */
    char const * cc, int len) /* The string data to make persistent */
{
  Trigger * nt;
  Table   * tab;
  int offset;
  TriggerStep * ss;

  /* Check that: 
     1. the trigger name does not already exist.
     2. the table (or view) does exist.
   */
  {
    char * tmp_str = sqliteStrNDup(nm->z, nm->n);
    if (sqliteHashFind(&(pParse->db->trigHash), tmp_str, nm->n + 1)) {
      sqliteSetNString(&pParse->zErrMsg, "trigger ", -1,
	  nm->z, nm->n, " already exists", -1, 0);
      sqliteFree(tmp_str);
      pParse->nErr++;
      goto trigger_cleanup;
    }
    sqliteFree(tmp_str);
  }
  {
    char * tmp_str = sqliteStrNDup(tbl->z, tbl->n);
    tab = sqliteFindTable(pParse->db, tmp_str);
    sqliteFree(tmp_str);
    if (!tab) {
      sqliteSetNString(&pParse->zErrMsg, "no such table: ", -1,
	  tbl->z, tbl->n, 0);
      pParse->nErr++;
      goto trigger_cleanup;
    }
  }

  /* Build the Trigger object */
  nt = (Trigger *)sqliteMalloc(sizeof(Trigger));

  nt->name = sqliteStrNDup(nm->z, nm->n);
  nt->table = sqliteStrNDup(tbl->z, tbl->n);
  nt->op = op;
  nt->tr_tm = tr_tm;
  nt->pWhen = pWhen;
  nt->pColumns = cols;
  nt->foreach = foreach;
  nt->step_list = steps;
  nt->isCommit = 0;

  nt->strings = sqliteStrNDup(cc, len);
  offset = (int)(nt->strings - cc);

  sqliteExprMoveStrings(nt->pWhen, offset);

  ss = nt->step_list;
  while (ss) {
    sqliteSelectMoveStrings(ss->pSelect, offset);
    if (ss->target.z) ss->target.z += offset;
    sqliteExprMoveStrings(ss->pWhere, offset);
    sqliteExprListMoveStrings(ss->pExprList, offset);

    ss = ss->pNext;
  }

  /* if we are not initializing, and this trigger is not on a TEMP table, 
     build the sqlite_master entry */
  if (!pParse->initFlag && !tab->isTemp) {

    /* Make an entry in the sqlite_master table */
    sqliteBeginWriteOperation(pParse);

    sqliteVdbeAddOp(pParse->pVdbe,        OP_OpenWrite, 0, 2);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, MASTER_NAME,           P3_STATIC);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_NewRecno,  0, 0);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_String,    0, 0);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, "trigger",             P3_STATIC);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_String,    0, 0);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->name,        0); 
    sqliteVdbeAddOp(pParse->pVdbe,        OP_String,    0, 0);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->table,        0); 
    sqliteVdbeAddOp(pParse->pVdbe,        OP_Integer,    0, 0);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_String,    0, 0);
    sqliteVdbeChangeP3(pParse->pVdbe, -1, nt->strings,     0);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_MakeRecord, 5, 0);
    sqliteVdbeAddOp(pParse->pVdbe,        OP_PutIntKey, 0, 1);

    /* Change the cookie, since the schema is changed */
    changeCookie(pParse->db);
    sqliteVdbeAddOp(pParse->pVdbe, OP_Integer, pParse->db->next_cookie, 0);
    sqliteVdbeAddOp(pParse->pVdbe, OP_SetCookie, 0, 0);

    sqliteVdbeAddOp(pParse->pVdbe,        OP_Close,     0, 0);

    sqliteEndWriteOperation(pParse);
  }

  if (!pParse->explain) {
    /* Stick it in the hash-table */
    sqliteHashInsert(&(pParse->db->trigHash), nt->name, nm->n + 1, nt);

    /* Attach it to the table object */
    nt->pNext = tab->pTrigger;
    tab->pTrigger = nt;
    return;
  } else {
    sqliteFree(nt->strings);
    sqliteFree(nt->name);
    sqliteFree(nt->table);
    sqliteFree(nt);
  }

trigger_cleanup:

  sqliteIdListDelete(cols);
  sqliteExprDelete(pWhen);
  {
    TriggerStep * pp;
    TriggerStep * nn;

    pp = steps;
    while (pp) {
      nn = pp->pNext;
      sqliteExprDelete(pp->pWhere);
      sqliteExprListDelete(pp->pExprList);
      sqliteSelectDelete(pp->pSelect);
      sqliteIdListDelete(pp->pIdList);
      sqliteFree(pp);
      pp = nn;
    }
  }
}

  TriggerStep * 
sqliteTriggerSelectStep(Select * s)
{
  TriggerStep * tt = sqliteMalloc(sizeof(TriggerStep));

  tt->op = TK_SELECT;
  tt->pSelect = s;
  tt->orconf = OE_Default;

  return tt;
}

TriggerStep * 
sqliteTriggerInsertStep(Token * tbl, IdList * col, ExprList * val, Select * s, int orconf)
{
  TriggerStep * tt = sqliteMalloc(sizeof(TriggerStep));

  assert(val == 0 || s == 0);
  assert(val != 0 || s != 0);

  tt->op = TK_INSERT;
  tt->pSelect = s;
  tt->target  = *tbl;
  tt->pIdList = col;
  tt->pExprList = val;
  tt->orconf = orconf;

  return tt;
}

TriggerStep * 
sqliteTriggerUpdateStep(Token * tbl, ExprList * val, Expr * w, int orconf)
{
  TriggerStep * tt = sqliteMalloc(sizeof(TriggerStep));

  tt->op = TK_UPDATE;
  tt->target  = *tbl;
  tt->pExprList = val;
  tt->pWhere = w;
  tt->orconf = orconf;

  return tt;
}

TriggerStep * 
sqliteTriggerDeleteStep(Token * tbl, Expr * w)
{
  TriggerStep * tt = sqliteMalloc(sizeof(TriggerStep));

  tt->op = TK_DELETE;
  tt->target  = *tbl;
  tt->pWhere = w;
  tt->orconf = OE_Default;

  return tt;
}


/* This does a recursive delete of the trigger structure */
void sqliteDeleteTrigger(Trigger * tt)
{
  TriggerStep * ts, * tc;
  ts = tt->step_list;

  while (ts) {
    tc = ts;
    ts = ts->pNext;

    sqliteExprDelete(tc->pWhere);
    sqliteExprListDelete(tc->pExprList);
    sqliteSelectDelete(tc->pSelect);
    sqliteIdListDelete(tc->pIdList);

    sqliteFree(tc);
  }

  sqliteFree(tt->name);
  sqliteFree(tt->table);
  sqliteExprDelete(tt->pWhen);
  sqliteIdListDelete(tt->pColumns);
  sqliteFree(tt->strings);
  sqliteFree(tt);
}

/*
 * "nested" is true if this is begin called as the result of a DROP TABLE
 */
void sqliteDropTrigger(Parse *pParse, Token * trigname, int nested)
{
  char * tmp_name;
  Trigger * trig;
  Table   * tbl;

  tmp_name = sqliteStrNDup(trigname->z, trigname->n);

  /* ensure that the trigger being dropped exists */
  trig = sqliteHashFind(&(pParse->db->trigHash), tmp_name, trigname->n + 1); 
  if (!trig) {
    sqliteSetNString(&pParse->zErrMsg, "no such trigger: ", -1,
	tmp_name, -1, 0);
    sqliteFree(tmp_name);
    return;
  }

  /*
   * If this is not an "explain", do the following:
   * 1. Remove the trigger from its associated table structure
   * 2. Move the trigger from the trigHash hash to trigDrop
   */
  if (!pParse->explain) {
    /* 1 */
    tbl = sqliteFindTable(pParse->db, trig->table);
    assert(tbl);
    if (tbl->pTrigger == trig) 
      tbl->pTrigger = trig->pNext;
    else {
      Trigger * cc = tbl->pTrigger;
      while (cc) {
	if (cc->pNext == trig) {
	  cc->pNext = cc->pNext->pNext;
	  break;
	}
	cc = cc->pNext;
      }
      assert(cc);
    }

    /* 2 */
    sqliteHashInsert(&(pParse->db->trigHash), tmp_name, 
	trigname->n + 1, NULL);
    sqliteHashInsert(&(pParse->db->trigDrop), trig->name, 
	trigname->n + 1, trig);
  }

  /* Unless this is a trigger on a TEMP TABLE, generate code to destroy the
   * database record of the trigger */
  if (!tbl->isTemp) {
    int base;
    static VdbeOp dropTrigger[] = {
      { OP_OpenWrite,  0, 2,        MASTER_NAME},
      { OP_Rewind,     0, ADDR(9),  0},
      { OP_String,     0, 0,        0}, /* 2 */
      { OP_MemStore,   1, 1,        0},
      { OP_MemLoad,    1, 0,        0}, /* 4 */
      { OP_Column,     0, 1,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(4),  0}, /* 8 */
      { OP_Integer,    0, 0,        0}, /* 9 */
      { OP_SetCookie,  0, 0,        0},
      { OP_Close,      0, 0,        0},
    };

    if (!nested) 
      sqliteBeginWriteOperation(pParse);

    base = sqliteVdbeAddOpList(pParse->pVdbe, 
	ArraySize(dropTrigger), dropTrigger);
    sqliteVdbeChangeP3(pParse->pVdbe, base+2, tmp_name, 0);

    if (!nested)
      changeCookie(pParse->db);

    sqliteVdbeChangeP1(pParse->pVdbe, base+9, pParse->db->next_cookie);

    if (!nested)
      sqliteEndWriteOperation(pParse);
  }

  sqliteFree(tmp_name);
}

static int checkColumnOverLap(IdList * ii, ExprList * ee)
{
  int i, e;
  if (!ii) return 1;
  if (!ee) return 1;

  for (i = 0; i < ii->nId; i++) 
    for (e = 0; e < ee->nExpr; e++) 
      if (!sqliteStrICmp(ii->a[i].zName, ee->a[e].zName))
	return 1;

  return 0; 
}

/* A global variable that is TRUE if we should always set up temp tables for
 * for triggers, even if there are no triggers to code. This is used to test 
 * how much overhead the triggers algorithm is causing.
 *
 * This flag can be set or cleared using the "trigger_overhead_test" pragma.
 * The pragma is not documented since it is not really part of the interface
 * to SQLite, just the test procedure.
*/
int always_code_trigger_setup = 0;

/*
 * Returns true if a trigger matching op, tr_tm and foreach that is NOT already
 * on the Parse objects trigger-stack (to prevent recursive trigger firing) is
 * found in the list specified as pTrigger.
 */
int sqliteTriggersExist(
    Parse * pParse, 
    Trigger * pTrigger,
    int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
    int tr_tm,              /* one of TK_BEFORE, TK_AFTER */
    int foreach,            /* one of TK_ROW or TK_STATEMENT */
    ExprList * pChanges)
{
  Trigger * tt;

  if (always_code_trigger_setup) return 1;

  tt = pTrigger;
  while (tt) {
    if (tt->op == op && tt->tr_tm == tr_tm && tt->foreach == foreach &&
	checkColumnOverLap(tt->pColumns, pChanges)) {
      TriggerStack * ss;
      ss = pParse->trigStack;
      while (ss && ss->pTrigger != pTrigger) ss = ss->pNext;
      if (!ss) return 1;
    }
    tt = tt->pNext;
  }

  return 0;
}

static int codeTriggerProgram(
	Parse *pParse,
	TriggerStep * program,
	int onError)
{
    TriggerStep * step = program;
    int orconf;

    while (step) {
	int saveNTab = pParse->nTab;
	orconf = (onError == OE_Default)?step->orconf:onError;
	pParse->trigStack->orconf = orconf;
	switch(step->op) {
	    case TK_SELECT: {
                int tmp_tbl = pParse->nTab++;
		sqliteVdbeAddOp(pParse->pVdbe, OP_OpenTemp, tmp_tbl, 0);
		sqliteVdbeAddOp(pParse->pVdbe, OP_KeyAsData, tmp_tbl, 1);
		sqliteSelect(pParse, step->pSelect, 
			SRT_Union, tmp_tbl, 0, 0, 0);
		sqliteVdbeAddOp(pParse->pVdbe, OP_Close, tmp_tbl, 0);
		pParse->nTab--;
		break;
			    }
	    case TK_UPDATE: {
                sqliteVdbeAddOp(pParse->pVdbe, OP_PushList, 0, 0);
		sqliteUpdate(pParse, &step->target, 
			sqliteExprListDup(step->pExprList), 
			sqliteExprDup(step->pWhere), orconf);
                sqliteVdbeAddOp(pParse->pVdbe, OP_PopList, 0, 0);
		break;
			    }
	    case TK_INSERT: {
                sqliteInsert(pParse, &step->target, 
			sqliteExprListDup(step->pExprList), 
			sqliteSelectDup(step->pSelect), 
			sqliteIdListDup(step->pIdList), orconf);
		break;
			    }
	    case TK_DELETE: {
		sqliteVdbeAddOp(pParse->pVdbe, OP_PushList, 0, 0);
                sqliteDeleteFrom(pParse, &step->target, 
			sqliteExprDup(step->pWhere)
			);
		sqliteVdbeAddOp(pParse->pVdbe, OP_PopList, 0, 0);
		break;
			    }
	    default:
			    assert(0);
	} 
	pParse->nTab = saveNTab;
	step = step->pNext;
    }

    return 0;
}

int sqliteCodeRowTrigger(
	Parse * pParse,  /* Parse context */
	int op,          /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
	ExprList * changes, /* Changes list for any UPDATE OF triggers */
	int tr_tm,       /* One of TK_BEFORE, TK_AFTER */
	Table * tbl,     /* The table to code triggers from */
	int newTable,    /* The indice of the "new" row to access */
	int oldTable,    /* The indice of the "old" row to access */
	int onError)     /* ON CONFLICT policy */
{
  Trigger * pTrigger;
  TriggerStack * pTriggerStack;


  assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
  assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER);

  assert(newTable != -1 || oldTable != -1);

  pTrigger = tbl->pTrigger;
  while (pTrigger) {
    int fire_this = 0;

    /* determine whether we should code this trigger */
    if (pTrigger->op == op && pTrigger->tr_tm == tr_tm && 
	pTrigger->foreach == TK_ROW) {
      fire_this = 1;
      pTriggerStack = pParse->trigStack;
      while (pTriggerStack) {
	if (pTriggerStack->pTrigger == pTrigger) fire_this = 0;
	pTriggerStack = pTriggerStack->pNext;
      }
      if (op == TK_UPDATE && pTrigger->pColumns &&
	  !checkColumnOverLap(pTrigger->pColumns, changes))
	fire_this = 0;
    }

    if (fire_this) {
      int endTrigger;
      IdList dummyTablist;
      Expr * whenExpr;

      dummyTablist.nId = 0;
      dummyTablist.a = 0;

      /* Push an entry on to the trigger stack */
      pTriggerStack = sqliteMalloc(sizeof(TriggerStack));
      pTriggerStack->pTrigger = pTrigger;
      pTriggerStack->newIdx = newTable;
      pTriggerStack->oldIdx = oldTable;
      pTriggerStack->pTab = tbl;
      pTriggerStack->pNext = pParse->trigStack;
      pParse->trigStack = pTriggerStack;

      /* code the WHEN clause */
      endTrigger = sqliteVdbeMakeLabel(pParse->pVdbe);
      whenExpr = sqliteExprDup(pTrigger->pWhen);
      if (sqliteExprResolveIds(pParse, 0, &dummyTablist, 0, whenExpr)) {
	pParse->trigStack = pParse->trigStack->pNext;
	sqliteFree(pTriggerStack);
	sqliteExprDelete(whenExpr);
	return 1;
      }
      sqliteExprIfFalse(pParse, whenExpr, endTrigger);
      sqliteExprDelete(whenExpr);

      codeTriggerProgram(pParse, pTrigger->step_list, onError); 

      /* Pop the entry off the trigger stack */
      pParse->trigStack = pParse->trigStack->pNext;
      sqliteFree(pTriggerStack);

      sqliteVdbeResolveLabel(pParse->pVdbe, endTrigger);
    }
    pTrigger = pTrigger->pNext;
  }

  return 0;
}

/*
 * Handle UPDATE and DELETE triggers on views
 */
void sqliteViewTriggers(Parse *pParse, Table *pTab, 
    Expr * pWhere, int onError, ExprList * pChanges)
{
  int oldIdx = -1;
  int newIdx = -1;
  int *aXRef = 0;   
  Vdbe *v;
  int endOfLoop;
  int startOfLoop;
  Select theSelect;
  Token tblNameToken;

  assert(pTab->pSelect);

  tblNameToken.z = pTab->zName;
  tblNameToken.n = strlen(pTab->zName);

  theSelect.isDistinct = 0;
  theSelect.pEList = sqliteExprListAppend(0, sqliteExpr(TK_ALL, 0, 0, 0), 0);
  theSelect.pSrc   = sqliteIdListAppend(0, &tblNameToken);
  theSelect.pWhere = pWhere;    pWhere = 0;
  theSelect.pGroupBy = 0;
  theSelect.pHaving = 0;
  theSelect.pOrderBy = 0;
  theSelect.op = TK_SELECT; /* ?? */
  theSelect.pPrior = 0;
  theSelect.nLimit = -1;
  theSelect.nOffset = -1;
  theSelect.zSelect = 0;
  theSelect.base = 0;

  v = sqliteGetVdbe(pParse);
  assert(v);
  sqliteBeginMultiWriteOperation(pParse);

  /* Allocate temp tables */
  oldIdx = pParse->nTab++;
  sqliteVdbeAddOp(v, OP_OpenTemp, oldIdx, 0);
  if (pChanges) {
    newIdx = pParse->nTab++;
    sqliteVdbeAddOp(v, OP_OpenTemp, newIdx, 0);
  }

  /* Snapshot the view */
  if (sqliteSelect(pParse, &theSelect, SRT_Table, oldIdx, 0, 0, 0)) {
    goto trigger_cleanup;
  }

  /* loop thru the view snapshot, executing triggers for each row */
  endOfLoop = sqliteVdbeMakeLabel(v);
  sqliteVdbeAddOp(v, OP_Rewind, oldIdx, endOfLoop);

  /* Loop thru the view snapshot, executing triggers for each row */
  startOfLoop = sqliteVdbeCurrentAddr(v);

  /* Build the updated row if required */
  if (pChanges) {
    int ii, jj;

    aXRef = sqliteMalloc( sizeof(int) * pTab->nCol );
    if( aXRef==0 ) goto trigger_cleanup;
    for (ii = 0; ii < pTab->nCol; ii++)
      aXRef[ii] = -1;

    for(ii=0; ii<pChanges->nExpr; ii++){
      int jj;
      if( sqliteExprResolveIds(pParse, oldIdx, theSelect.pSrc , 0, 
	    pChanges->a[ii].pExpr) )
	goto trigger_cleanup;

      if( sqliteExprCheck(pParse, pChanges->a[ii].pExpr, 0, 0) )
	goto trigger_cleanup;

      for(jj=0; jj<pTab->nCol; jj++){
	if( sqliteStrICmp(pTab->aCol[jj].zName, pChanges->a[ii].zName)==0 ){
	  aXRef[jj] = ii;
	  break;
	}
      }
      if( jj>=pTab->nCol ){
	sqliteSetString(&pParse->zErrMsg, "no such column: ", 
	    pChanges->a[ii].zName, 0);
	pParse->nErr++;
	goto trigger_cleanup;
      }
    }

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);

    for (ii = 0; ii < pTab->nCol; ii++)
      if( aXRef[ii] < 0 ) 
	sqliteVdbeAddOp(v, OP_Column, oldIdx, ii);
      else
	sqliteExprCode(pParse, pChanges->a[aXRef[ii]].pExpr);

    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_BEFORE, 
	pTab, newIdx, oldIdx, onError);
    sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, 
	pTab, newIdx, oldIdx, onError);
  } else {
    sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_BEFORE, pTab, -1, oldIdx, 
	onError);
    sqliteCodeRowTrigger(pParse, TK_DELETE, 0, TK_AFTER, pTab, -1, oldIdx, 
	onError);
  }

  sqliteVdbeAddOp(v, OP_Next, oldIdx, startOfLoop);

  sqliteVdbeResolveLabel(v, endOfLoop);
  sqliteEndWriteOperation(pParse);

trigger_cleanup:
  sqliteFree(aXRef);
  sqliteExprListDelete(pChanges);
  sqliteExprDelete(pWhere);
  sqliteExprListDelete(theSelect.pEList);
  sqliteIdListDelete(theSelect.pSrc);
  sqliteExprDelete(theSelect.pWhere);
  return;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.36 2002/03/03 18:59:41 drh Exp $
** $Id: update.c,v 1.37 2002/05/15 08:30:14 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(

                         ** an expression for the i-th column of the table.
                         ** aXRef[i]==-1 if the i-th column is not changed. */
  int openOp;            /* Opcode used to open tables */
  int chngRecno;         /* True if the record number is being changed */
  Expr *pRecnoExpr;      /* Expression defining the new record number */
  int openAll;           /* True if all indices need to be opened */

  int row_triggers_exist = 0;

  int newIdx      = -1;  /* index of trigger "new" temp table       */
  int oldIdx      = -1;  /* index of trigger "old" temp table       */

  if( pParse->nErr || sqlite_malloc_failed ) goto update_cleanup;
  db = pParse->db;

  /* Check for the special case of a VIEW with one or more ON UPDATE triggers 
   * defined 
   */
  {
    char * zTab = sqliteTableNameFromToken(pTableName);

    if(zTab != 0) {
      pTab = sqliteFindTable(pParse->db, zTab);
      if (pTab) {
	row_triggers_exist = 
	  sqliteTriggersExist(pParse, pTab->pTrigger, 
	      TK_UPDATE, TK_BEFORE, TK_ROW, pChanges) ||
	  sqliteTriggersExist(pParse, pTab->pTrigger, 
	      TK_UPDATE, TK_AFTER, TK_ROW, pChanges);
      }
      sqliteFree(zTab);
      if (row_triggers_exist &&  pTab->pSelect ) {
	/* Just fire VIEW triggers */
	sqliteViewTriggers(pParse, pTab, pWhere, onError, pChanges);
	return;
      }
    }
  }

  /* Locate the table which we want to update.  This table has to be
  ** put in an IdList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect
  ** an IdList* parameter instead of just a Table* parameter.
  */
  pTabList = sqliteTableTokenToIdList(pParse, pTableName);
  if( pTabList==0 ) goto update_cleanup;
  pTab = pTabList->a[0].pTab;
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  aXRef = sqliteMalloc( sizeof(int) * pTab->nCol );
  if( aXRef==0 ) goto update_cleanup;
  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

  if (row_triggers_exist) {
    newIdx = pParse->nTab++;
    oldIdx = pParse->nTab++;
  }

  /* Resolve the column names in all the expressions in both the
  ** WHERE clause and in the new values.  Also find the column index
  ** for each column to be updated in the pChanges array.
  */
  base = pParse->nTab++;
  if( pWhere ){

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* Initialize the count of updated rows
  */
  if( db->flags & SQLITE_CountRows ){
  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
    sqliteVdbeAddOp(v, OP_Integer, 0, 0);
  }

  if (row_triggers_exist) {
    int ii;

    sqliteVdbeAddOp(v, OP_OpenTemp, oldIdx, 0);
    sqliteVdbeAddOp(v, OP_OpenTemp, newIdx, 0);

    sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
    addr = sqliteVdbeAddOp(v, OP_ListRead, 0, 0);
    sqliteVdbeAddOp(v, OP_Dup, 0, 0);

    sqliteVdbeAddOp(v, OP_Dup, 0, 0);
    sqliteVdbeAddOp(v, OP_Open, base, pTab->tnum);
    sqliteVdbeAddOp(v, OP_MoveTo, base, 0);

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for (ii = 0; ii < pTab->nCol; ii++) {
	if (ii == pTab->iPKey) 
	    sqliteVdbeAddOp(v, OP_Recno, base, 0);
	else
	    sqliteVdbeAddOp(v, OP_Column, base, ii);
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, oldIdx, 0);

    sqliteVdbeAddOp(v, OP_Integer, 13, 0);
    for (ii = 0; ii < pTab->nCol; ii++){
      if( aXRef[ii] < 0 ){
        if (ii == pTab->iPKey)
          sqliteVdbeAddOp(v, OP_Recno, base, 0);
        else
          sqliteVdbeAddOp(v, OP_Column, base, ii);
      }else{
        sqliteExprCode(pParse, pChanges->a[aXRef[ii]].pExpr);
      }
    }
    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    sqliteVdbeAddOp(v, OP_PutIntKey, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Close, base, 0);

    sqliteVdbeAddOp(v, OP_Rewind, oldIdx, 0);
    sqliteVdbeAddOp(v, OP_Rewind, newIdx, 0);

    if (sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_BEFORE, pTab, 
	  newIdx, oldIdx, onError)) goto update_cleanup;
  }

  /* Rewind the list of records that need to be updated and
  ** open every index that needs updating.  Note that if any
  ** index could potentially invoke a REPLACE conflict resolution 
  ** action, then we need to open all indices because we might need
  ** to be deleting some records.
  */
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
  openOp = pTab->isTemp ? OP_OpenWrAux : OP_OpenWrite;
  sqliteVdbeAddOp(v, openOp, base, pTab->tnum);
  if( onError==OE_Replace ){
    openAll = 1;
  }else{
    openAll = 0;
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){

  /* Loop over every record that needs updating.  We have to load
  ** the old data for each record to be updated because some columns
  ** might not change and we will need to copy the old value.
  ** Also, the old data is needed to delete the old index entires.
  ** So make the cursor point at the old record.
  */
  if (!row_triggers_exist) {
    int ii;
    sqliteVdbeAddOp(v, OP_ListRewind, 0, 0);
  addr = sqliteVdbeAddOp(v, OP_ListRead, 0, 0);
  sqliteVdbeAddOp(v, OP_Dup, 0, 0);
    addr = sqliteVdbeAddOp(v, OP_ListRead, 0, 0);
    sqliteVdbeAddOp(v, OP_Dup, 0, 0);
  }
  sqliteVdbeAddOp(v, OP_MoveTo, base, 0);

  /* If the record number will change, push the record number as it
  ** will be after the update. (The old record number is currently
  ** on top of the stack.)
  */
  if( chngRecno ){

  /* Delete the old indices for the current record.
  */
  sqliteGenerateRowIndexDelete(v, pTab, base, aIdxUsed);

  /* If changing the record number, delete the old record.
  */
  if( chngRecno ){
    sqliteVdbeAddOp(v, OP_Delete, 0, 0);
    sqliteVdbeAddOp(v, OP_Delete, base, 0);
  }

  /* Create the new index entries and the new record.
  */
  sqliteCompleteInsertion(pParse, pTab, base, aIdxUsed, chngRecno, 1);

  /* Increment the row counter 
  */
  if( db->flags & SQLITE_CountRows ){
  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqliteVdbeAddOp(v, OP_AddImm, 1, 0);
  }

  if (row_triggers_exist) {
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] )
	sqliteVdbeAddOp(v, OP_Close, base+i+1, 0);
    }
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    pParse->nTab = base;

    if (sqliteCodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, pTab, 
	  newIdx, oldIdx, onError)) goto update_cleanup;
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqliteVdbeAddOp(v, OP_Goto, 0, addr);
  sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
  sqliteVdbeAddOp(v, OP_ListReset, 0, 0);

  /* Close all tables if there were no FOR EACH ROW triggers */
  if (!row_triggers_exist) {
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] ){
	sqliteVdbeAddOp(v, OP_Close, base+i+1, 0);
      }
    }
    sqliteVdbeAddOp(v, OP_Close, base, 0);
    pParse->nTab = base;
  } else {
    sqliteVdbeAddOp(v, OP_Close, newIdx, 0);
    sqliteVdbeAddOp(v, OP_Close, oldIdx, 0);
  }

  sqliteEndWriteOperation(pParse);

  /*
  ** Return the number of rows that were changed.
  */
  if( db->flags & SQLITE_CountRows ){
  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
    sqliteVdbeAddOp(v, OP_ColumnCount, 1, 0);
    sqliteVdbeAddOp(v, OP_ColumnName, 0, 0);
    sqliteVdbeChangeP3(v, -1, "rows updated", P3_STATIC);
    sqliteVdbeAddOp(v, OP_Callback, 1, 0);
  }

update_cleanup:

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.141 2002/05/10 13:14:07 drh Exp $
** $Id: vdbe.c,v 1.142 2002/05/15 08:30:14 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test

  Mem *aMem;          /* The memory locations */
  Agg agg;            /* Aggregate information */
  int nSet;           /* Number of sets allocated */
  Set *aSet;          /* An array of sets */
  int nCallback;      /* Number of callbacks invoked so far */
  int iLimit;         /* Limit on the number of callbacks remaining */
  int iOffset;        /* Offset before beginning to do callbacks */

  int keylistStackDepth; 
  Keylist ** keylistStack;
};

/*
** Create a new virtual database engine.
*/
Vdbe *sqliteVdbeCreate(sqlite *db){
  Vdbe *p;

  AggReset(&p->agg);
  for(i=0; i<p->nSet; i++){
    sqliteHashClear(&p->aSet[i].hash);
  }
  sqliteFree(p->aSet);
  p->aSet = 0;
  p->nSet = 0;
  if (p->keylistStackDepth > 0) {
    int ii;
    for (ii = 0; ii < p->keylistStackDepth; ii++) {
      KeylistFree(p->keylistStack[ii]);
    }
    sqliteFree(p->keylistStack);
    p->keylistStackDepth = 0;
    p->keylistStack = 0;
  }
}

/*
** Delete an entire VDBE.
*/
void sqliteVdbeDelete(Vdbe *p){
  int i;

  "MustBeInt",         "Add",               "AddImm",            "Subtract",
  "Multiply",          "Divide",            "Remainder",         "BitAnd",
  "BitOr",             "BitNot",            "ShiftLeft",         "ShiftRight",
  "AbsValue",          "Eq",                "Ne",                "Lt",
  "Le",                "Gt",                "Ge",                "IsNull",
  "NotNull",           "Negative",          "And",               "Or",
  "Not",               "Concat",            "Noop",              "Function",
  "Limit",           
  "Limit",             "PushList",          "PopList",           
};

/*
** Given the name of an opcode, return its number.  Return 0 if
** there is no match.
**
** This routine is used for testing and debugging.

  if( VERIFY( i>=0 && i<p->nSet &&) 
       sqliteHashFind(&p->aSet[i].hash, zStack[tos], aStack[tos].n)){
    pc = pOp->p2 - 1;
  }
  POPSTACK;
  break;
}

/* Opcode: PushList * * * 
**
** Save the current Vdbe list such that it can be restored by a PopList 
** opcode. The list is empty after this is executed.
*/
case OP_PushList: {
  p->keylistStackDepth++;
  assert(p->keylistStackDepth > 0);
  p->keylistStack = sqliteRealloc(p->keylistStack, 
	  sizeof(Keylist *) * p->keylistStackDepth);
  p->keylistStack[p->keylistStackDepth - 1] = p->pList;
  p->pList = 0;
  break;
}

/* Opcode: PopList * * * 
**
** Restore the Vdbe list to the state it was in when PushList was last
** executed.
*/
case OP_PopList: {
  assert(p->keylistStackDepth > 0);
  p->keylistStackDepth--;
  KeylistFree(p->pList);
  p->pList = p->keylistStack[p->keylistStackDepth];
  p->keylistStack[p->keylistStackDepth] = 0;
  if (p->keylistStackDepth == 0) {
    sqliteFree(p->keylistStack);
    p->keylistStack = 0;
  }
  break;
}

/* Opcode: SetNotFound P1 P2 *
**
** Pop the stack once and compare the value popped off with the
** contents of set P1.  If the element popped does not exists in 
** set P1, then jump to P2.  Otherwise fall through.
*/

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.50 2002/04/20 14:24:43 drh Exp $
** $Id: vdbe.h,v 1.51 2002/05/15 08:30:14 danielk1977 Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines

#define OP_Not               109
#define OP_Concat            110
#define OP_Noop              111
#define OP_Function          112

#define OP_Limit             113

#define OP_PushList          114
#define OP_PopList           115

#define OP_MAX               113
#define OP_MAX               115

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqliteVdbeCreate(sqlite*);
void sqliteVdbeCreateCallback(Vdbe*, int*);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.41 2002/04/30 19:20:29 drh Exp $
** $Id: where.c,v 1.42 2002/05/15 08:30:14 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.

  memset(aExpr, 0, sizeof(aExpr));
  nExpr = exprSplit(ARRAYSIZE(aExpr), aExpr, pWhere);

  /* Analyze all of the subexpressions.
  */
  for(i=0; i<nExpr; i++){
    exprAnalyze(base, &aExpr[i]);
    if (pParse->trigStack && pParse->trigStack->newIdx >= 0) {
	aExpr[i].prereqRight = 
	    aExpr[i].prereqRight & ~(1 << pParse->trigStack->newIdx - base);
	aExpr[i].prereqLeft = 
	    aExpr[i].prereqLeft & ~(1 << pParse->trigStack->newIdx - base);
	aExpr[i].prereqAll = 
	    aExpr[i].prereqAll & ~(1 << pParse->trigStack->newIdx - base);
    }
    if (pParse->trigStack && pParse->trigStack->oldIdx >= 0) {
	aExpr[i].prereqRight = 
	    aExpr[i].prereqRight & ~(1 << pParse->trigStack->oldIdx - base);
	aExpr[i].prereqLeft = 
	    aExpr[i].prereqLeft & ~(1 << pParse->trigStack->oldIdx - base);
	aExpr[i].prereqAll = 
	    aExpr[i].prereqAll & ~(1 << pParse->trigStack->oldIdx - base);
    }
  }

  /* Figure out a good nesting order for the tables.  aOrder[0] will
  ** be the index in pTabList of the outermost table.  aOrder[1] will
  ** be the first nested loop and so on.  aOrder[pTabList->nId-1] will
  ** be the innermost loop.
  **

# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file tests creating and dropping triggers, and interaction thereof
# with the database COMMIT/ROLLBACK logic.
#
# 1. CREATE and DROP TRIGGER tests
# trig-1.1: Error if table does not exist
# trig-1.2: Error if trigger already exists
# trig-1.3: Created triggers are deleted if the transaction is rolled back
# trig-1.4: DROP TRIGGER removes trigger
# trig-1.5: Dropped triggers are restored if the transaction is rolled back
# trig-1.6: Error if dropped trigger doesn't exist
# trig-1.7: Dropping the table automatically drops all triggers
# trig-1.8: A trigger created on a TEMP table is not inserted into sqlite_master
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test trig_cd-1.1 {
   catchsql {
     CREATE TRIGGER trig UPDATE ON no_such_table BEGIN
       SELECT * from sqlite_master;
     END;
   } 
} {1 {no such table: no_such_table}}

execsql {
    CREATE TABLE t1(a);
}
execsql {
	CREATE TRIGGER tr1 INSERT ON t1 BEGIN
	  INSERT INTO t1 values(1);
 	END;
}
do_test trig_cd-1.2 {
    catchsql {
	CREATE TRIGGER tr1 DELETE ON t1 BEGIN
	    SELECT * FROM sqlite_master;
 	END
     }
} {1 {trigger tr1 already exists}}

do_test trig_cd-1.3 {
    catchsql {
	BEGIN;
	CREATE TRIGGER tr2 INSERT ON t1 BEGIN
	    SELECT * from sqlite_master; END;
        ROLLBACK;
	CREATE TRIGGER tr2 INSERT ON t1 BEGIN
	    SELECT * from sqlite_master; END;
    }
} {0 {}}

do_test trig_cd-1.4 {
    catchsql {
	DROP TRIGGER tr1;
	CREATE TRIGGER tr1 DELETE ON t1 BEGIN
	    SELECT * FROM sqlite_master;
	END
    }
} {0 {}}

do_test trig_cd-1.5 {
    execsql {
	BEGIN;
	DROP TRIGGER tr2;
	ROLLBACK;
	DROP TRIGGER tr2;
    }
} {}

do_test trig_cd-1.6 {
    catchsql {
	DROP TRIGGER biggles;
    }
} {1 {no such trigger: biggles}}

do_test trig_cd-1.7 {
    catchsql {
	DROP TABLE t1;
	DROP TRIGGER tr1;
    }
} {1 {no such trigger: tr1}}

execsql {
  CREATE TEMP TABLE temp_table(a);
}
do_test trig_cd-1.8 {
  execsql {
	CREATE TRIGGER temp_trig UPDATE ON temp_table BEGIN
	    SELECT * from sqlite_master;
	END;
	SELECT count(*) FROM sqlite_master WHERE name = 'temp_trig';
  } 
} {0}

catchsql {
  DROP TABLE temp_table;
}
catchsql {
  DROP TABLE t1;
}

finish_test

# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Regression testing of FOR EACH ROW table triggers
#
# 1. Trigger execution order tests. 
# These tests ensure that BEFORE and AFTER triggers are fired at the correct
# times relative to each other and the triggering statement. 
#
# trig-1.1.*: ON UPDATE trigger execution model.
# trig-1.2.*: DELETE trigger execution model.
# trig-1.3.*: INSERT trigger execution model.
#
# 2. Trigger program execution tests.
# These tests ensure that trigger programs execute correctly (ie. that a
# trigger program can correctly execute INSERT, UPDATE, DELETE * SELECT
# statements, and combinations thereof).
#
# 3. Selective trigger execution 
# This tests that conditional triggers (ie. UPDATE OF triggers and triggers
# with WHEN clauses) are fired only fired when they are supposed to be.
#
# trig-3.1: UPDATE OF triggers
# trig-3.2: WHEN clause
#
# 4. Cascaded trigger execution 
# Tests that trigger-programs may cause other triggers to fire. Also that a 
# trigger-program is never executed recursively.
# 
# trig-4.1: Trivial cascading trigger
# trig-4.2: Trivial recursive trigger handling 
#
# 5. Count changes behaviour.
# Verify that rows altered by triggers are not included in the return value
# of the "count changes" interface.
#
# 6. ON CONFLICT clause handling
# trig-6.1[a-f]: INSERT statements
# trig-6.2[a-f]: UPDATE statements
#
# 7. Triggers on views fire correctly.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# 1.
set ii 0
foreach tbl_defn [ list \
	{CREATE TABLE tbl (a, b);} \
	{CREATE TABLE tbl (a INTEGER PRIMARY KEY, b);} \
        {CREATE TABLE tbl (a, b PRIMARY KEY);} \
	{CREATE TABLE tbl (a, b); CREATE INDEX tbl_idx ON tbl(b);} ] {
  incr ii
  catchsql { DROP INDEX tbl_idx; }
  catchsql {
    DROP TABLE rlog;
    DROP TABLE clog;
    DROP TABLE tbl;
    DROP TABLE other_tbl;
  }

  execsql $tbl_defn

  execsql {
    INSERT INTO tbl VALUES(1, 2);
    INSERT INTO tbl VALUES(3, 4);

    CREATE TABLE rlog (idx, old_a, old_b, db_sum_a, db_sum_b, new_a, new_b);
    CREATE TABLE clog (idx, old_a, old_b, db_sum_a, db_sum_b, new_a, new_b);

    CREATE TRIGGER before_update_row BEFORE UPDATE ON tbl FOR EACH ROW 
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  old.a, old.b, 
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  new.a, new.b);
    END;

    CREATE TRIGGER after_update_row AFTER UPDATE ON tbl FOR EACH ROW 
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  old.a, old.b, 
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  new.a, new.b);
    END;

    CREATE TRIGGER conditional_update_row AFTER UPDATE ON tbl FOR EACH ROW
      WHEN old.a = 1
      BEGIN
      INSERT INTO clog VALUES ( (SELECT max(idx) + 1 FROM clog), 
	  old.a, old.b, 
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  new.a, new.b);
    END;
  }

  do_test trig-1.1.$ii {
    execsql {
      UPDATE tbl SET a = a * 10, b = b * 10;
      SELECT * FROM rlog ORDER BY idx;
      SELECT * FROM clog ORDER BY idx;
    }
  } [list 1 1 2  4  6 10 20 \
          2 1 2 13 24 10 20 \
	  3 3 4 13 24 30 40 \
	  4 3 4 40 60 30 40 \
          1 1 2 13 24 10 20 ]
  
  execsql {
    DELETE FROM rlog;
    DELETE FROM tbl;
    INSERT INTO tbl VALUES (100, 100);
    INSERT INTO tbl VALUES (300, 200);
    CREATE TRIGGER delete_before_row BEFORE DELETE ON tbl FOR EACH ROW
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  old.a, old.b, 
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  0, 0);
    END;

    CREATE TRIGGER delete_after_row AFTER DELETE ON tbl FOR EACH ROW
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  old.a, old.b, 
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  0, 0);
    END;
  }
  do_test trig-1.2.$ii {
    execsql {
      DELETE FROM tbl;
      SELECT * FROM rlog;
    }
  } [list 1 100 100 400 300 0 0 \
          2 100 100 300 200 0 0 \
          3 300 200 300 200 0 0 \
          4 300 200 0 0 0 0 ]

  execsql {
    DELETE FROM rlog;
    CREATE TRIGGER insert_before_row BEFORE INSERT ON tbl FOR EACH ROW
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  0, 0,
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  new.a, new.b);
    END;

    CREATE TRIGGER insert_after_row AFTER INSERT ON tbl FOR EACH ROW
      BEGIN
      INSERT INTO rlog VALUES ( (SELECT max(idx) + 1 FROM rlog), 
	  0, 0,
	  (SELECT sum(a) FROM tbl), (SELECT sum(b) FROM tbl), 
	  new.a, new.b);
    END;
  }
  do_test trig-1.3.$ii {
    execsql {

      CREATE TABLE other_tbl(a, b);
      INSERT INTO other_tbl VALUES(1, 2);
      INSERT INTO other_tbl VALUES(3, 4);
      -- INSERT INTO tbl SELECT * FROM other_tbl;
      INSERT INTO tbl VALUES(5, 6);
      DROP TABLE other_tbl;

      SELECT * FROM rlog;
    }
  } [list 1 0 0 0 0 5 6 \
          2 0 0 5 6 5 6 ]
}
catchsql {
  DROP TABLE rlog;
  DROP TABLE clog;
  DROP TABLE tbl;
  DROP TABLE other_tbl;
}

# 2.
set ii 0
foreach tr_program [ list \
   {UPDATE tbl SET b = old.b;} \
  {INSERT INTO log VALUES(new.c, 2, 3);} \
  {DELETE FROM log WHERE a = 1;} \
  {INSERT INTO tbl VALUES(500, new.b * 10, 700); 
    UPDATE tbl SET c = old.c; 
    DELETE FROM log;} \
  {INSERT INTO log select * from tbl;} 
   ] \
{
  foreach test_varset [ list \
    {
      set statement {UPDATE tbl SET c = 10 WHERE a = 1;} 
      set prep      {INSERT INTO tbl VALUES(1, 2, 3);}
      set newC 10
      set newB 2
      set newA 1
      set oldA 1
      set oldB 2
      set oldC 3
    } \
    {
      set statement {DELETE FROM tbl WHERE a = 1;}
      set prep      {INSERT INTO tbl VALUES(1, 2, 3);}
      set oldA 1
      set oldB 2
      set oldC 3
    } \
    {
      set statement {INSERT INTO tbl VALUES(1, 2, 3);}
      set newA 1
      set newB 2
      set newC 3
    }
  ] \
  {
    set statement {}
    set prep {}
    set newA {''}
    set newB {''}
    set newC {''}
    set oldA {''}
    set oldB {''}
    set oldC {''}

    incr ii

    eval $test_varset

    set statement_type [string range $statement 0 5]
    set tr_program_fixed $tr_program
    if {$statement_type == "DELETE"} {
      regsub -all new\.a $tr_program_fixed {''} tr_program_fixed 
      regsub -all new\.b $tr_program_fixed {''} tr_program_fixed 
      regsub -all new\.c $tr_program_fixed {''} tr_program_fixed 
    }
    if {$statement_type == "INSERT"} {
      regsub -all old\.a $tr_program_fixed {''} tr_program_fixed 
      regsub -all old\.b $tr_program_fixed {''} tr_program_fixed 
      regsub -all old\.c $tr_program_fixed {''} tr_program_fixed 
    }


    set tr_program_cooked $tr_program
    regsub -all new\.a $tr_program_cooked $newA tr_program_cooked 
    regsub -all new\.b $tr_program_cooked $newB tr_program_cooked 
    regsub -all new\.c $tr_program_cooked $newC tr_program_cooked 
    regsub -all old\.a $tr_program_cooked $oldA tr_program_cooked 
    regsub -all old\.b $tr_program_cooked $oldB tr_program_cooked 
    regsub -all old\.c $tr_program_cooked $oldC tr_program_cooked 

    catchsql {
      DROP TABLE tbl;
      DROP TABLE log;
    }
    execsql {
      CREATE TABLE tbl(a PRIMARY KEY, b, c);
      CREATE TABLE log(a, b, c);
    }

    set query {SELECT * FROM tbl; SELECT * FROM log;}
    set prep "$prep; INSERT INTO log VALUES(1, 2, 3); INSERT INTO log VALUES(10, 20, 30);"

# Check execution of BEFORE programs:

    set before_data [ execsql "$prep $tr_program_cooked $statement $query" ]

    execsql "DELETE FROM tbl; DELETE FROM log; $prep";
    execsql "CREATE TRIGGER the_trigger BEFORE [string range $statement 0 6] ON tbl BEGIN $tr_program_fixed END;"

    do_test trig-2-$ii-before "execsql {$statement $query}" $before_data

    execsql "DROP TRIGGER the_trigger;"
    execsql "DELETE FROM tbl; DELETE FROM log;"

# Check execution of AFTER programs
    set after_data [ execsql "$prep $statement $tr_program_cooked $query" ]

    execsql "DELETE FROM tbl; DELETE FROM log; $prep";

    execsql "CREATE TRIGGER the_trigger AFTER [string range $statement 0 6] ON tbl BEGIN $tr_program_fixed END;"

    do_test trig-2-$ii-after "execsql {$statement $query}" $after_data
    execsql "DROP TRIGGER the_trigger;"
  }
}
catchsql {
  DROP TABLE tbl;
  DROP TABLE log;
}

# 3.

# trig-3.1: UPDATE OF triggers
execsql {
  CREATE TABLE tbl (a, b, c, d);
  CREATE TABLE log (a);
  INSERT INTO log VALUES (0);
  INSERT INTO tbl VALUES (0, 0, 0, 0);
  INSERT INTO tbl VALUES (1, 0, 0, 0);
  CREATE TRIGGER tbl_after_update_cd BEFORE UPDATE OF c, d ON tbl
    BEGIN
      UPDATE log SET a = a + 1;
    END;
}
do_test trig-3.1 {
  execsql {
    UPDATE tbl SET b = 1, c = 10; -- 2
    UPDATE tbl SET b = 10; -- 0
    UPDATE tbl SET d = 4 WHERE a = 0; --1
    UPDATE tbl SET a = 4, b = 10; --0
    SELECT * FROM log;
  }
} {3}
execsql {
  DROP TABLE tbl;
  DROP TABLE log;
}

# trig-3.2: WHEN clause
set when_triggers [ list \
             {t1 BEFORE INSERT ON tbl WHEN new.a > 20} \
             {t2 BEFORE INSERT ON tbl WHEN (SELECT count(*) FROM tbl) = 0} ]

execsql {
  CREATE TABLE tbl (a, b, c, d);
  CREATE TABLE log (a);
  INSERT INTO log VALUES (0);
}

foreach trig $when_triggers {
  execsql "CREATE TRIGGER $trig BEGIN UPDATE log set a = a + 1; END;"
}

do_test trig-3.2 {
  execsql { 

    INSERT INTO tbl VALUES(0, 0, 0, 0);     -- 1
    SELECT * FROM log;
    UPDATE log SET a = 0;

    INSERT INTO tbl VALUES(0, 0, 0, 0);     -- 0
    SELECT * FROM log;
    UPDATE log SET a = 0;

    INSERT INTO tbl VALUES(200, 0, 0, 0);     -- 1
    SELECT * FROM log;
    UPDATE log SET a = 0;
  }
} {1 0 1}
execsql {
  DROP TABLE tbl;
  DROP TABLE log;
}

# Simple cascaded trigger
execsql {
  CREATE TABLE tblA(a, b);
  CREATE TABLE tblB(a, b);
  CREATE TABLE tblC(a, b);

  CREATE TRIGGER tr1 BEFORE INSERT ON tblA BEGIN
    INSERT INTO tblB values(new.a, new.b);
  END;

  CREATE TRIGGER tr2 BEFORE INSERT ON tblB BEGIN
    INSERT INTO tblC values(new.a, new.b);
  END;
}
do_test trig-4.1 {
  execsql {
    INSERT INTO tblA values(1, 2);
    SELECT * FROM tblA;
    SELECT * FROM tblB;
    SELECT * FROM tblC;
  }
} {1 2 1 2 1 2}
execsql {
  DROP TABLE tblA;
  DROP TABLE tblB;
  DROP TABLE tblC;
}

# Simple recursive trigger
execsql {
  CREATE TABLE tbl(a, b, c);
  CREATE TRIGGER tbl_trig BEFORE INSERT ON tbl 
    BEGIN
      INSERT INTO tbl VALUES (new.a, new.b, new.c);
    END;
}
do_test trig-4.2 {
  execsql {
    INSERT INTO tbl VALUES (1, 2, 3);
    select * from tbl;
  }
} {1 2 3 1 2 3}
execsql {
  DROP TABLE tbl;
}

# 5.
execsql {
  CREATE TABLE tbl(a, b, c);
  CREATE TRIGGER tbl_trig BEFORE INSERT ON tbl 
    BEGIN
      INSERT INTO tbl VALUES (1, 2, 3);
      INSERT INTO tbl VALUES (2, 2, 3);
      UPDATE tbl set b = 10 WHERE a = 1;
      DELETE FROM tbl WHERE a = 1;
      DELETE FROM tbl;
    END;
}
do_test trig-5 {
  execsql {
    INSERT INTO tbl VALUES(100, 200, 300);
  }
  db changes
} {1}
execsql {
  DROP TABLE tbl;
}


# Handling of ON CONFLICT by INSERT statements inside triggers
execsql {
  CREATE TABLE tbl (a primary key, b, c);
  CREATE TRIGGER ai_tbl AFTER INSERT ON tbl BEGIN
    INSERT OR IGNORE INTO tbl values (new.a, 0, 0);
  END;
}
do_test trig-6.1a {
  execsql {
    BEGIN;
    INSERT INTO tbl values (1, 2, 3);
    SELECT * from tbl;
  }
} {1 2 3}
do_test trig-6.1b {
  catchsql {
    INSERT OR ABORT INTO tbl values (2, 2, 3);
  }
} {1 {constraint failed}}
do_test trig-6.1c {
  execsql {
    SELECT * from tbl;
  }
} {1 2 3}
do_test trig-6.1d {
  catchsql {
    INSERT OR FAIL INTO tbl values (2, 2, 3);
  }
} {1 {constraint failed}}
do_test trig-6.1e {
  execsql {
    SELECT * from tbl;
  }
} {1 2 3 2 2 3}
do_test trig-6.1f {
  execsql {
    INSERT OR REPLACE INTO tbl values (2, 2, 3);
    SELECT * from tbl;
  }
} {1 2 3 2 0 0}
do_test trig-6.1g {
  catchsql {
    INSERT OR ROLLBACK INTO tbl values (3, 2, 3);
  }
} {1 {constraint failed}}
do_test trig-6.1h {
  execsql {
    SELECT * from tbl;
  }
} {}


# Handling of ON CONFLICT by UPDATE statements inside triggers
execsql {
  INSERT INTO tbl values (4, 2, 3);
  INSERT INTO tbl values (6, 3, 4);
  CREATE TRIGGER au_tbl AFTER UPDATE ON tbl BEGIN
    UPDATE OR IGNORE tbl SET a = new.a, c = 10;
  END;
}
do_test trig-6.2a {
  execsql {
    BEGIN;
    UPDATE tbl SET a = 1 WHERE a = 4;
    SELECT * from tbl;
  }
} {1 2 10 6 3 4}
do_test trig-6.2b {
  catchsql {
    UPDATE OR ABORT tbl SET a = 4 WHERE a = 1;
  }
} {1 {constraint failed}}
do_test trig-6.2c {
  execsql {
    SELECT * from tbl;
  }
} {1 2 10 6 3 4}
do_test trig-6.2d {
  catchsql {
    UPDATE OR FAIL tbl SET a = 4 WHERE a = 1;
  }
} {1 {constraint failed}}
do_test trig-6.2e {
  execsql {
    SELECT * from tbl;
  }
} {4 2 10 6 3 4}
do_test trig-6.2f {
  execsql {
    UPDATE OR REPLACE tbl SET a = 1 WHERE a = 4;
    SELECT * from tbl;
  }
} {1 3 10}
execsql {
  INSERT INTO tbl VALUES (2, 3, 4);
}
do_test trig-6.2g {
  catchsql {
    UPDATE OR ROLLBACK tbl SET a = 4 WHERE a = 1;
  }
} {1 {constraint failed}}
do_test trig-6.2h {
  execsql {
    SELECT * from tbl;
  }
} {4 2 3 6 3 4}
execsql {
  DROP TABLE tbl;
}

# 7. Triggers on views
execsql {
  CREATE TABLE ab(a, b);
  CREATE TABLE cd(c, d);
  INSERT INTO ab VALUES (1, 2);
  INSERT INTO ab VALUES (0, 0);
  INSERT INTO cd VALUES (3, 4);

  CREATE TABLE tlog(ii INTEGER PRIMARY KEY, 
      olda, oldb, oldc, oldd, newa, newb, newc, newd);

  CREATE VIEW abcd AS SELECT a, b, c, d FROM ab, cd;

  CREATE TRIGGER before_update BEFORE UPDATE ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	old.a, old.b, old.c, old.d, new.a, new.b, new.c, new.d);
  END;
  CREATE TRIGGER after_update AFTER UPDATE ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	old.a, old.b, old.c, old.d, new.a, new.b, new.c, new.d);
  END;

  CREATE TRIGGER before_delete BEFORE DELETE ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	old.a, old.b, old.c, old.d, 0, 0, 0, 0);
  END;
  CREATE TRIGGER after_delete AFTER DELETE ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	old.a, old.b, old.c, old.d, 0, 0, 0, 0);
  END;

  CREATE TRIGGER before_insert BEFORE INSERT ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	0, 0, 0, 0, new.a, new.b, new.c, new.d);
  END;
   CREATE TRIGGER after_insert AFTER INSERT ON abcd BEGIN
    INSERT INTO tlog VALUES(NULL, 
	0, 0, 0, 0, new.a, new.b, new.c, new.d);
   END;
}

do_test trig-7 {
  execsql {
    UPDATE abcd SET a = 100, b = 5*5 WHERE a = 1;
    DELETE FROM abcd WHERE a = 1;
    INSERT INTO abcd VALUES(10, 20, 30, 40);
    SELECT * FROM tlog;
  }
} [ list 1 1 2 3 4 100 25 3 4 \
         2 1 2 3 4 100 25 3 4 \
 3 1 2 3 4 0 0 0 0 4 1 2 3 4 0 0 0 0 \
 5 0 0 0 0 10 20 30 40 6 0 0 0 0 10 20 30 40 ]

finish_test

#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: lang.tcl,v 1.33 2002/05/06 11:47:33 drh Exp $}
set rcsid {$Id: lang.tcl,v 1.34 2002/05/15 08:30:15 danielk1977 Exp $}

puts {<html>
<head>
  <title>Query Language Understood By SQLite</title>
</head>
<body bgcolor=white>
<h1 align=center>

  {EXPLAIN explain}
  {expression expr}
  {{BEGIN TRANSACTION} transaction}
  {PRAGMA pragma}
  {{ON CONFLICT clause} conflict}
  {{CREATE VIEW} createview}
  {{DROP VIEW} dropview}
  {{CREATE TRIGGER} createtrigger}
  {{DROP TRIGGER} droptrigger}
}] {
  puts "<li><a href=\"#[lindex $section 1]\">[lindex $section 0]</a></li>"
}
puts {</ul></p>

<p>Details on the implementation of each command are provided in
the sequel.</p>

table or index then it is suppose to clean up the named table or index.
In version 1.0 of SQLite, the VACUUM command would invoke 
<b>gdbm_reorganize()</b> to clean up the backend database file.
Beginning with version 2.0 of SQLite, GDBM is no longer used for
the database backend and VACUUM has become a no-op.
</p>
}

Section {CREATE TRIGGER} createtrigger

Syntax {sql-statement} {
CREATE TRIGGER <trigger-name> [ BEFORE | AFTER ]
<database-event>
<trigger-action>
}

Syntax {database-event} {
DELETE | 
INSERT | 
UPDATE | 
UPDATE OF <column-list>
ON <table-name> 
}

Syntax {trigger-action} {
[ FOR EACH ROW ] [ WHEN <expression> ] 
BEGIN 
  <trigger-step> ; [ <trigger-step> ; ]*
END
}

Syntax {trigger-step} {
<update-statement> | <insert-statement> | 
<delete-statement> | <select-statement> 
}

puts {
<p>The CREATE TRIGGER statement is used to add triggers to the 
database schema. Triggers are database operations (the <i>trigger-action</i>) 
that are automatically performed when a specified database event (the
<i>database-event</i>) occurs.  </p>

<p>A trigger may be specified to fire whenever a DELETE, INSERT or UPDATE of a
particular database table occurs, or whenever an UPDATE of one or more
specified columns of a table are updated.</p>

<p>At this time SQLite supports only FOR EACH ROW triggers, not FOR EACH
STATEMENT triggers. Hence explicitly specifying FOR EACH ROW is optional.  FOR
EACH ROW implies that the SQL statements specified as <i>trigger-steps</i> 
may be executed (depending on the WHEN clause) for each database row being
inserted, updated or deleted by the statement causing the trigger to fire.</p>

<p>Both the WHEN clause and the <i>trigger-steps</i> may access elements of 
the row being inserted, deleted or updated using references of the form 
"NEW.<i>column-name</i>" and "OLD.<i>column-name</i>", where
<i>column-name</i> is the name of a column from the table that the trigger
is associated with. OLD and NEW references may only be used in triggers on
<i>trigger-event</i>s for which they are relevant, as follows:</p>

<table border=0 cellpadding=10>
<tr>
<td valign="top" align="right" width=120><i>INSERT</i></td>
<td valign="top">NEW references are valid</td>
</tr>
<tr>
<td valign="top" align="right" width=120><i>UPDATE</i></td>
<td valign="top">NEW and OLD references are valid</td>
</tr>
<tr>
<td valign="top" align="right" width=120><i>DELETE</i></td>
<td valign="top">OLD references are valid</td>
</tr>
</table>
</p>

<p>If a WHEN clause is supplied, the SQL statements specified as <i>trigger-steps</i> are only executed for rows for which the WHEN clause is true. If no WHEN clause is supplied, the SQL statements are executed for all rows.</p>

<p>The specified <i>trigger-time</i> determines when the <i>trigger-steps</i>
will be executed relative to the insertion, modification or removal of the
associated row.</p>

<p>An ON CONFLICT clause may be specified as part of an UPDATE or INSERT
<i>trigger-step</i>. However if an ON CONFLICT clause is specified as part of 
the statement causing the trigger to fire, then this conflict handling
policy is used instead.</p>

<p>Triggers are automatically dropped when the table that they are 
associated with is dropped.</p>

<p>Triggers may be created on views, as well as ordinary tables. If one or
more INSERT, DELETE or UPDATE triggers are defined on a view, then it is not
an error to execute an INSERT, DELETE or UPDATE statement on the view, 
respectively. Thereafter, executing an INSERT, DELETE or UPDATE on the view
causes the associated triggers to fire. The real tables underlying the view
are not modified (except possibly explicitly, by a trigger program).</p>

<p><b>Example:</b></p>

<p>Assuming that customer records are stored in the "customers" table, and
that order records are stored in the "orders" table, the following trigger
ensures that all associated orders are redirected when a customer changes
his or her address:</p>
}
Example {
CREATE TRIGGER update_customer_address UPDATE OF address ON customers 
  BEGIN
    UPDATE orders SET address = new.address WHERE customer_name = old.name;
  END;
}
puts {
<p>With this trigger installed, executing the statement:</p>
}
Example {
UPDATE customers SET address = '1 Main St.' WHERE name = 'Jack Jones';
}
puts {
<p>causes the following to be automatically executed:</p>
}
Example {
UPDATE orders SET address = '1 Main St.' WHERE customer_name = 'Jack Jones';
}

Section {DROP TRIGGER} droptrigger
Syntax {sql-statement} {
DROP TRIGGER <trigger-name>
}
puts { 
  <p>Used to drop a trigger from the database schema. Note that triggers
  are automatically dropped when the associated table is dropped.</p>
}


puts {
<p><hr /></p>
<p><a href="index.html"><img src="/goback.jpg" border=0 />
Back to the SQLite Home Page</a>
</p>

</body></html>}