**     COPY
**     VACUUM
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.78 2002/02/21 12:01:27 drh 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 
................................................................................
    pParse->pVdbe = 0;
    pParse->colNamesSet = 0;
    pParse->rc = rc;
    pParse->schemaVerified = 0;
  }
}

/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function
** is responsible for making sure the node eventually gets freed.
*/
Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    sqliteExprDelete(pLeft);
    sqliteExprDelete(pRight);
    return 0;
  }
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = "";
    pNew->token.n = 0;
  }
  if( pLeft && pRight ){
    sqliteExprSpan(pNew, &pLeft->span, &pRight->span);
  }else{
    pNew->span = pNew->token;
  }
  return pNew;
}

/*
** Set the Expr.token field of the given expression to span all
** text between the two given tokens.
*/
void sqliteExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
  if( pExpr ){
    pExpr->span.z = pLeft->z;
    pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    sqliteExprListDelete(pList);
    return 0;
  }
  pNew->op = TK_FUNCTION;
  pNew->pList = pList;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = "";
    pNew->token.n = 0;
  }
  return pNew;
}

/*
** Locate the in-memory structure that describes 
** a particular database table given the name
** of that table.  Return NULL if not found.
*/
Table *sqliteFindTable(sqlite *db, char *zName){
  Table *p = sqliteHashFind(&db->tblHash, zName, strlen(zName)+1);
  return p;
}

/*
** Locate the in-memory structure that describes 
** a particular index given the name of that index.
** Return NULL if not found.
*/
Index *sqliteFindIndex(sqlite *db, char *zName){
  Index *p = sqliteHashFind(&db->idxHash, zName, strlen(zName)+1);
  return p;
}

/*
** Remove the given index from the index hash table, and free
** its memory structures.
................................................................................
  }
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    sqliteDeleteIndex(db, pIndex);
  }
  sqliteFree(pTable->zName);
  sqliteFree(pTable->aCol);

  sqliteFree(pTable);
}

/*
** Unlink the given table from the hash tables and the delete the
** table structure with all its indices.
*/
................................................................................
      sqliteVdbeAddOp(v, op, 1, 0);
      pParse->nTab = 2;
      sqliteSelect(pParse, pSelect, SRT_Table, 1);
    }
    sqliteEndWriteOperation(pParse);
  }
}














































/*
** Given a token, look up a table with that name.  If not found, leave
** an error for the parser to find and return NULL.
*/
Table *sqliteTableFromToken(Parse *pParse, Token *pTok){
  char *zName;
................................................................................
  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( pTab->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName, 
      " may not have new indices added", 0);
    pParse->nErr++;
    goto exit_create_index;
  }






  /* If this index is created while re-reading the schema from sqlite_master
  ** but the table associated with this index is a temporary table, it can
  ** only mean that the table that this index is really associated with is
  ** one whose name is hidden behind a temporary table with the same name.
  ** Since its table has been suppressed, we need to also suppress the
  ** index.
................................................................................
  */
  if( !pParse->explain ){
    sqlitePendingDropIndex(db, pIndex);
    db->flags |= SQLITE_InternChanges;
  }
}

/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqliteExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  int i;
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
    if( pList==0 ){
      sqliteExprDelete(pExpr);
      return 0;
    }
  }
  if( (pList->nExpr & 7)==0 ){
    int n = pList->nExpr + 8;
    struct ExprList_item *a;
    a = sqliteRealloc(pList->a, n*sizeof(pList->a[0]));
    if( a==0 ){
      sqliteExprDelete(pExpr);
      return pList;
    }
    pList->a = a;
  }
  if( pExpr || pName ){
    i = pList->nExpr++;
    pList->a[i].pExpr = pExpr;
    pList->a[i].zName = 0;
    if( pName ){
      sqliteSetNString(&pList->a[i].zName, pName->z, pName->n, 0);
      sqliteDequote(pList->a[i].zName);
    }
  }
  return pList;
}

/*
** Delete an entire expression list.
*/
void sqliteExprListDelete(ExprList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nExpr; i++){
    sqliteExprDelete(pList->a[i].pExpr);
    sqliteFree(pList->a[i].zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
IdList *sqliteIdListAppend(IdList *pList, Token *pToken){
................................................................................
    int i = pList->nId - 1;
    sqliteSetNString(&pList->a[i].zAlias, pToken->z, pToken->n, 0);
    sqliteDequote(pList->a[i].zAlias);
  }
}

/*
** Delete an entire IdList
*/
void sqliteIdListDelete(IdList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nId; i++){
    sqliteFree(pList->a[i].zName);
    sqliteFree(pList->a[i].zAlias);





    if( pList->a[i].pSelect ){
      sqliteFree(pList->a[i].zName);

      sqliteSelectDelete(pList->a[i].pSelect);
      sqliteDeleteTable(0, pList->a[i].pTab);
    }
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

**     COPY
**     VACUUM
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.79 2002/02/23 02:32:10 drh 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 
................................................................................
    pParse->pVdbe = 0;
    pParse->colNamesSet = 0;
    pParse->rc = rc;
    pParse->schemaVerified = 0;
  }
}

/*































































** Locate the in-memory structure that describes 
** a particular database table given the name
** of that table.  Return NULL if not found.
*/
Table *sqliteFindTable(sqlite *db, const char *zName){
  Table *p = sqliteHashFind(&db->tblHash, zName, strlen(zName)+1);
  return p;
}

/*
** Locate the in-memory structure that describes 
** a particular index given the name of that index.
** Return NULL if not found.
*/
Index *sqliteFindIndex(sqlite *db, const char *zName){
  Index *p = sqliteHashFind(&db->idxHash, zName, strlen(zName)+1);
  return p;
}

/*
** Remove the given index from the index hash table, and free
** its memory structures.
................................................................................
  }
  for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
    pNext = pIndex->pNext;
    sqliteDeleteIndex(db, pIndex);
  }
  sqliteFree(pTable->zName);
  sqliteFree(pTable->aCol);
  sqliteSelectDelete(pTable->pSelect);
  sqliteFree(pTable);
}

/*
** Unlink the given table from the hash tables and the delete the
** table structure with all its indices.
*/
................................................................................
      sqliteVdbeAddOp(v, op, 1, 0);
      pParse->nTab = 2;
      sqliteSelect(pParse, pSelect, SRT_Table, 1);
    }
    sqliteEndWriteOperation(pParse);
  }
}

/*
** The parser calls this routine in order to create a new VIEW
*/
void sqliteCreateView(
  Parse *pParse,     /* The parsing context */
  Token *pBegin,     /* The CREATE token that begins the statement */
  Token *pName,      /* The token that holds the name of the view */
  Select *pSelect    /* A SELECT statement that will become the new view */
){
  Token sEnd;
  Table *pSelTab;
  Table *p;
  char *z;
  int n, offset;

  sqliteStartTable(pParse, pBegin, pName, 0);
  p = pParse->pNewTable;
  if( p==0 ) goto create_view_failed;
  p->pSelect = pSelect;
  pSelTab = sqliteResultSetOfSelect(pParse, 0, pSelect);
  if( pSelTab==0 ) goto create_view_failed;
  assert( p->aCol==0 );
  p->nCol = pSelTab->nCol;
  p->aCol = pSelTab->aCol;
  pSelTab->nCol = 0;
  pSelTab->aCol = 0;
  sqliteDeleteTable(0, pSelTab);
  sEnd = pParse->sLastToken;
  if( sEnd.z[0]!=0 && sEnd.z[0]!=';' ){
    sEnd.z += sEnd.n;
  }
  sEnd.n = 0;
  n = ((int)sEnd.z) - (int)pBegin->z;
  z = p->pSelect->zSelect = sqliteStrNDup(pBegin->z, n+1);
  if( z==0 ) goto create_view_failed;
  offset = ((int)z) - (int)pBegin->z;
  sqliteSelectMoveStrings(p->pSelect, offset);
  sqliteEndTable(pParse, &sEnd, 0);
  return;

create_view_failed:
  sqliteSelectDelete(pSelect);
  return;
}

/*
** Given a token, look up a table with that name.  If not found, leave
** an error for the parser to find and return NULL.
*/
Table *sqliteTableFromToken(Parse *pParse, Token *pTok){
  char *zName;
................................................................................
  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( pTab->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName, 
      " may not have new indices added", 0);
    pParse->nErr++;
    goto exit_create_index;
  }
  if( pTab->pSelect ){
    sqliteSetString(&pParse->zErrMsg, "views may not be indexed", 0);
    pParse->nErr++;
    goto exit_create_index;
  }

  /* If this index is created while re-reading the schema from sqlite_master
  ** but the table associated with this index is a temporary table, it can
  ** only mean that the table that this index is really associated with is
  ** one whose name is hidden behind a temporary table with the same name.
  ** Since its table has been suppressed, we need to also suppress the
  ** index.
................................................................................
  */
  if( !pParse->explain ){
    sqlitePendingDropIndex(db, pIndex);
    db->flags |= SQLITE_InternChanges;
  }
}


















































/*
** Append a new element to the given IdList.  Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
IdList *sqliteIdListAppend(IdList *pList, Token *pToken){
................................................................................
    int i = pList->nId - 1;
    sqliteSetNString(&pList->a[i].zAlias, pToken->z, pToken->n, 0);
    sqliteDequote(pList->a[i].zAlias);
  }
}

/*
** Delete an entire IdList.
*/
void sqliteIdListDelete(IdList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nId; i++){
    sqliteFree(pList->a[i].zName);
    sqliteFree(pList->a[i].zAlias);

    /* If the pSelect field is set and is not pointing to the Select
    ** structure that defines a VIEW, then the Select is for a subquery
    ** and should be deleted.  Do not delete VIEWs, however.
    */
    if( pList->a[i].pSelect && 

         (pList->a[i].pTab==0 || pList->a[i].pTab->pSelect==0) ){
      sqliteSelectDelete(pList->a[i].pSelect);
      sqliteDeleteTable(0, pList->a[i].pTab);
    }
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

**    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 1.26 2002/01/31 15:54:22 drh Exp $
*/
#include "sqliteInt.h"


















































/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(
  Parse *pParse,         /* The parser context */
  Token *pTableName,     /* The table from which we should delete things */
  Expr *pWhere           /* The WHERE clause.  May be null */
................................................................................
  db = pParse->db;

  /* 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 = sqliteIdListAppend(0, pTableName);
  if( pTabList==0 ) goto delete_from_cleanup;
  for(i=0; i<pTabList->nId; i++){
    pTabList->a[i].pTab = sqliteFindTable(db, pTabList->a[i].zName);
    if( pTabList->a[i].pTab==0 ){
      sqliteSetString(&pParse->zErrMsg, "no such table: ", 
         pTabList->a[i].zName, 0);
      pParse->nErr++;
      goto delete_from_cleanup;
    }
    if( pTabList->a[i].pTab->readOnly ){
      sqliteSetString(&pParse->zErrMsg, "table ", pTabList->a[i].zName,
        " may not be modified", 0);
      pParse->nErr++;
      goto delete_from_cleanup;
    }
  }
  pTab = pTabList->a[0].pTab;

  /* Resolve the column names in all the expressions.
  */
  if( pWhere ){
    sqliteExprResolveInSelect(pParse, pWhere);
    if( sqliteExprResolveIds(pParse, pTabList, 0, pWhere) ){

**    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 1.27 2002/02/23 02:32:10 drh 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
** everything checks out, return a pointer to the Table structure.
*/
Table *sqliteTableNameToTable(Parse *pParse, const char *zTab){
  Table *pTab;
  pTab = sqliteFindTable(pParse->db, zTab);
  if( pTab==0 ){
    sqliteSetString(&pParse->zErrMsg, "no such table: ", zTab, 0);
    pParse->nErr++;
    return 0;
  }
  if( pTab->readOnly || pTab->pSelect ){
    sqliteSetString(&pParse->zErrMsg, 
      pTab->pSelect ? "view " : "table ",
      zTab,
      " may not be modified", 0);
    pParse->nErr++;
    return 0;      
  }
  return pTab;
}

/*
** Given a table name, check to make sure the table exists, is writable
** and is not a view.  If everything is OK, construct an IdList holding
** the table and return a pointer to the IdList.  The calling function
** is responsible for freeing the IdList when it has finished with it.
** If there is an error, leave a message on pParse->zErrMsg and return
** NULL.
*/
IdList *sqliteTableTokenToIdList(Parse *pParse, Token *pTableName){
  Table *pTab;
  IdList *pTabList;

  pTabList = sqliteIdListAppend(0, pTableName);
  if( pTabList==0 ) return 0;
  assert( pTabList->nId==1 );
  pTab = sqliteTableNameToTable(pParse, pTabList->a[0].zName);
  if( pTab==0 ){
    sqliteIdListDelete(pTabList);
    return 0;
  }
  pTabList->a[0].pTab = pTab;
  return pTabList;
}

/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(
  Parse *pParse,         /* The parser context */
  Token *pTableName,     /* The table from which we should delete things */
  Expr *pWhere           /* The WHERE clause.  May be null */
................................................................................
  db = pParse->db;

  /* 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;















  pTab = pTabList->a[0].pTab;

  /* Resolve the column names in all the expressions.
  */
  if( pWhere ){
    sqliteExprResolveInSelect(pParse, pWhere);
    if( sqliteExprResolveIds(pParse, pTabList, 0, pWhere) ){

**    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 1.41 2002/02/14 21:42:51 drh Exp $
*/
#include "sqliteInt.h"

































































/*
** Recursively delete an expression tree.
*/
void sqliteExprDelete(Expr *p){
  if( p==0 ) return;
  if( p->op!=TK_AS ){
................................................................................
    if( p->pLeft ) sqliteExprDelete(p->pLeft);
    if( p->pRight ) sqliteExprDelete(p->pRight);
  }
  if( p->pList ) sqliteExprListDelete(p->pList);
  if( p->pSelect ) sqliteSelectDelete(p->pSelect);
  sqliteFree(p);
}







































































































/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables.
*/
int sqliteExprIsConstant(Expr *p){
  switch( p->op ){
................................................................................
    **         "SELECT a+b AS 'x' FROM t1".)
    **
    **     3.  One of the special names "ROWID", "OID", or "_ROWID_".
    */
    case TK_ID: {
      int cnt = 0;      /* Number of matches */
      int i;            /* Loop counter */


      char *z = sqliteStrNDup(pExpr->token.z, pExpr->token.n);
      sqliteDequote(z);
      if( z==0 ) return 1;
      for(i=0; i<pTabList->nId; i++){
        int j;
        Table *pTab = pTabList->a[i].pTab;
        if( pTab==0 ) continue;
        for(j=0; j<pTab->nCol; j++){
................................................................................
      int cntTab = 0;          /* Number of matching tables */
      int i;                   /* Loop counter */
      Expr *pLeft, *pRight;    /* Left and right subbranches of the expr */
      char *zLeft, *zRight;    /* Text of an identifier */

      pLeft = pExpr->pLeft;
      pRight = pExpr->pRight;
      assert( pLeft && pLeft->op==TK_ID );
      assert( pRight && pRight->op==TK_ID );
      zLeft = sqliteStrNDup(pLeft->token.z, pLeft->token.n);
      zRight = sqliteStrNDup(pRight->token.z, pRight->token.n);
      if( zLeft==0 || zRight==0 ){
        sqliteFree(zLeft);
        sqliteFree(zRight);
        return 1;
      }
................................................................................
        for(i=0; i<pExpr->pList->nExpr; i++){
          Expr *pE2 = pExpr->pList->a[i].pExpr;
          switch( pE2->op ){
            case TK_FLOAT:
            case TK_INTEGER:
            case TK_STRING: {
              int addr = sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0);

              sqliteVdbeChangeP3(v, addr, pE2->token.z, pE2->token.n);
              sqliteVdbeDequoteP3(v, addr);
              break;
            }
            default: {
              sqliteExprCode(pParse, pE2);
              sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0);
................................................................................
        sqliteVdbeAddOp(v, OP_Recno, pExpr->iTable, 0);
      }
      break;
    }
    case TK_FLOAT:
    case TK_INTEGER: {
      sqliteVdbeAddOp(v, OP_String, 0, 0);

      sqliteVdbeChangeP3(v, -1, pExpr->token.z, pExpr->token.n);
      break;
    }
    case TK_STRING: {
      int addr = sqliteVdbeAddOp(v, OP_String, 0, 0);

      sqliteVdbeChangeP3(v, addr, pExpr->token.z, pExpr->token.n);
      sqliteVdbeDequoteP3(v, addr);
      break;
    }
    case TK_NULL: {
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      break;

**    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 1.42 2002/02/23 02:32:10 drh 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
** is responsible for making sure the node eventually gets freed.
*/
Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    sqliteExprDelete(pLeft);
    sqliteExprDelete(pRight);
    return 0;
  }
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = 0;
    pNew->token.n = 0;
  }
  if( pLeft && pRight ){
    sqliteExprSpan(pNew, &pLeft->span, &pRight->span);
  }else{
    pNew->span = pNew->token;
  }
  return pNew;
}

/*
** Set the Expr.token field of the given expression to span all
** text between the two given tokens.
*/
void sqliteExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
  if( pExpr ){
    pExpr->span.z = pLeft->z;
    pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    sqliteExprListDelete(pList);
    return 0;
  }
  pNew->op = TK_FUNCTION;
  pNew->pList = pList;
  if( pToken ){
    pNew->token = *pToken;
  }else{
    pNew->token.z = 0;
    pNew->token.n = 0;
  }
  return pNew;
}

/*
** Recursively delete an expression tree.
*/
void sqliteExprDelete(Expr *p){
  if( p==0 ) return;
  if( p->op!=TK_AS ){
................................................................................
    if( p->pLeft ) sqliteExprDelete(p->pLeft);
    if( p->pRight ) sqliteExprDelete(p->pRight);
  }
  if( p->pList ) sqliteExprListDelete(p->pList);
  if( p->pSelect ) sqliteSelectDelete(p->pSelect);
  sqliteFree(p);
}

/*
** The following group of functions are used to translate the string
** pointers of tokens in expression from one buffer to another.
**
** Normally, the Expr.token.z and Expr.span.z fields point into the
** original input buffer of an SQL statement.  This is usually OK
** since the SQL statement is executed and the expression is deleted
** before the input buffer is freed.  Making the tokens point to the
** original input buffer saves many calls to malloc() and thus helps
** the library to run faster. 
**
** But sometimes we need an expression to persist past the time when
** the input buffer is freed.  (Example: The SELECT clause of a
** CREATE VIEW statement contains expressions that must persist for
** the life of the view.)  When that happens we have to make a
** persistent copy of the input buffer and translate the Expr.token.z
** and Expr.span.z fields to point to the copy rather than the 
** original input buffer.  The following group of routines to that
** translation.
**
** The "offset" parameter is the distance from the original input buffer
** to the persistent copy.  These routines recursively walk the entire
** expression tree and shift all tokens by "offset" amount.
**
** The work of figuring out the appropriate "offset" and making the
** presistent copy of the input buffer is done by the calling routine.
*/
void sqliteExprMoveStrings(Expr *p, int offset){
  if( p==0 ) return;
  if( p->token.z ) p->token.z += offset;
  if( p->span.z ) p->span.z += offset;
  if( p->pLeft ) sqliteExprMoveStrings(p->pLeft, offset);
  if( p->pRight ) sqliteExprMoveStrings(p->pRight, offset);
  if( p->pList ) sqliteExprListMoveStrings(p->pList, offset);
  if( p->pSelect ) sqliteSelectMoveStrings(p->pSelect, offset);
}
void sqliteExprListMoveStrings(ExprList *pList, int offset){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nExpr; i++){
    sqliteExprMoveStrings(pList->a[i].pExpr, offset);
  }
}
void sqliteSelectMoveStrings(Select *pSelect, int offset){
  if( pSelect==0 ) return;
  sqliteExprListMoveStrings(pSelect->pEList, offset);
  sqliteExprMoveStrings(pSelect->pWhere, offset);
  sqliteExprListMoveStrings(pSelect->pGroupBy, offset);
  sqliteExprMoveStrings(pSelect->pHaving, offset);
  sqliteExprListMoveStrings(pSelect->pOrderBy, offset);
  sqliteSelectMoveStrings(pSelect->pPrior, offset);
}

/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqliteExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  int i;
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
    if( pList==0 ){
      sqliteExprDelete(pExpr);
      return 0;
    }
  }
  if( (pList->nExpr & 7)==0 ){
    int n = pList->nExpr + 8;
    struct ExprList_item *a;
    a = sqliteRealloc(pList->a, n*sizeof(pList->a[0]));
    if( a==0 ){
      sqliteExprDelete(pExpr);
      return pList;
    }
    pList->a = a;
  }
  if( pExpr || pName ){
    i = pList->nExpr++;
    pList->a[i].pExpr = pExpr;
    pList->a[i].zName = 0;
    if( pName ){
      sqliteSetNString(&pList->a[i].zName, pName->z, pName->n, 0);
      sqliteDequote(pList->a[i].zName);
    }
  }
  return pList;
}

/*
** Delete an entire expression list.
*/
void sqliteExprListDelete(ExprList *pList){
  int i;
  if( pList==0 ) return;
  for(i=0; i<pList->nExpr; i++){
    sqliteExprDelete(pList->a[i].pExpr);
    sqliteFree(pList->a[i].zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables.
*/
int sqliteExprIsConstant(Expr *p){
  switch( p->op ){
................................................................................
    **         "SELECT a+b AS 'x' FROM t1".)
    **
    **     3.  One of the special names "ROWID", "OID", or "_ROWID_".
    */
    case TK_ID: {
      int cnt = 0;      /* Number of matches */
      int i;            /* Loop counter */
      char *z;
      assert( pExpr->token.z );
      z = sqliteStrNDup(pExpr->token.z, pExpr->token.n);
      sqliteDequote(z);
      if( z==0 ) return 1;
      for(i=0; i<pTabList->nId; i++){
        int j;
        Table *pTab = pTabList->a[i].pTab;
        if( pTab==0 ) continue;
        for(j=0; j<pTab->nCol; j++){
................................................................................
      int cntTab = 0;          /* Number of matching tables */
      int i;                   /* Loop counter */
      Expr *pLeft, *pRight;    /* Left and right subbranches of the expr */
      char *zLeft, *zRight;    /* Text of an identifier */

      pLeft = pExpr->pLeft;
      pRight = pExpr->pRight;
      assert( pLeft && pLeft->op==TK_ID && pLeft->token.z );
      assert( pRight && pRight->op==TK_ID && pRight->token.z );
      zLeft = sqliteStrNDup(pLeft->token.z, pLeft->token.n);
      zRight = sqliteStrNDup(pRight->token.z, pRight->token.n);
      if( zLeft==0 || zRight==0 ){
        sqliteFree(zLeft);
        sqliteFree(zRight);
        return 1;
      }
................................................................................
        for(i=0; i<pExpr->pList->nExpr; i++){
          Expr *pE2 = pExpr->pList->a[i].pExpr;
          switch( pE2->op ){
            case TK_FLOAT:
            case TK_INTEGER:
            case TK_STRING: {
              int addr = sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0);
              assert( pE2->token.z );
              sqliteVdbeChangeP3(v, addr, pE2->token.z, pE2->token.n);
              sqliteVdbeDequoteP3(v, addr);
              break;
            }
            default: {
              sqliteExprCode(pParse, pE2);
              sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0);
................................................................................
        sqliteVdbeAddOp(v, OP_Recno, pExpr->iTable, 0);
      }
      break;
    }
    case TK_FLOAT:
    case TK_INTEGER: {
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      assert( pExpr->token.z );
      sqliteVdbeChangeP3(v, -1, pExpr->token.z, pExpr->token.n);
      break;
    }
    case TK_STRING: {
      int addr = sqliteVdbeAddOp(v, OP_String, 0, 0);
      assert( pExpr->token.z );
      sqliteVdbeChangeP3(v, addr, pExpr->token.z, pExpr->token.n);
      sqliteVdbeDequoteP3(v, addr);
      break;
    }
    case TK_NULL: {
      sqliteVdbeAddOp(v, OP_String, 0, 0);
      break;

**    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 1.44 2002/02/19 13:39:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)
................................................................................
  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(db, zTab);
  sqliteFree(zTab);
  if( pTab==0 ){
    sqliteSetNString(&pParse->zErrMsg, "no such table: ", 0, 
        pTableName->z, pTableName->n, 0);
    pParse->nErr++;
    goto insert_cleanup;
  }
  if( pTab->readOnly ){
    sqliteSetString(&pParse->zErrMsg, "table ", pTab->zName,
        " may not be modified", 0);
    pParse->nErr++;
    goto insert_cleanup;
  }

  /* Allocate a VDBE
  */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pSelect ){
    sqliteBeginMultiWriteOperation(pParse);

**    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 1.45 2002/02/23 02:32:10 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following forms:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)
................................................................................
  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 = sqliteTableNameToTable(pParse, zTab);
  sqliteFree(zTab);




  if( pTab==0 ) goto insert_cleanup;








  /* Allocate a VDBE
  */
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;
  if( pSelect ){
    sqliteBeginMultiWriteOperation(pParse);

**
*************************************************************************
** 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 1.52 2002/02/18 22:49:59 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
%default_type {Token}
%extra_argument {Parse *pParse}
%syntax_error {
  sqliteSetString(&pParse->zErrMsg,"syntax error",0);
................................................................................
resolvetype(A) ::= FAIL.                     { A = OE_Fail; }
resolvetype(A) ::= IGNORE.                   { A = OE_Ignore; }
resolvetype(A) ::= REPLACE.                  { A = OE_Replace; }

////////////////////////// The DROP TABLE /////////////////////////////////////
//
cmd ::= DROP TABLE ids(X).          {sqliteDropTable(pParse,&X);}










//////////////////////// The SELECT statement /////////////////////////////////
//
cmd ::= select(X).  {
  sqliteSelect(pParse, X, SRT_Callback, 0);
  sqliteSelectDelete(X);
}

**
*************************************************************************
** 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 1.53 2002/02/23 02:32:10 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
%default_type {Token}
%extra_argument {Parse *pParse}
%syntax_error {
  sqliteSetString(&pParse->zErrMsg,"syntax error",0);
................................................................................
resolvetype(A) ::= FAIL.                     { A = OE_Fail; }
resolvetype(A) ::= IGNORE.                   { A = OE_Ignore; }
resolvetype(A) ::= REPLACE.                  { A = OE_Replace; }

////////////////////////// The DROP TABLE /////////////////////////////////////
//
cmd ::= DROP TABLE ids(X).          {sqliteDropTable(pParse,&X);}

///////////////////// The CREATE VIEW statement /////////////////////////////
//
cmd ::= CREATE(X) VIEW ids(Y) AS select(S). {
  sqliteCreateView(pParse, &X, &Y, S);
}
cmd ::= DROP VIEW ids(X). {
  sqliteDropTable(pParse, &X);
}

//////////////////////// The SELECT statement /////////////////////////////////
//
cmd ::= select(X).  {
  sqliteSelect(pParse, X, SRT_Callback, 0);
  sqliteSelectDelete(X);
}

**    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 SELECT statements in SQLite.
**
** $Id: select.c,v 1.64 2002/02/21 12:01:27 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/
................................................................................
  sqliteExprListDelete(p->pEList);
  sqliteIdListDelete(p->pSrc);
  sqliteExprDelete(p->pWhere);
  sqliteExprListDelete(p->pGroupBy);
  sqliteExprDelete(p->pHaving);
  sqliteExprListDelete(p->pOrderBy);
  sqliteSelectDelete(p->pPrior);

  sqliteFree(p);
}

/*
** Delete the aggregate information from the parse structure.
*/
static void sqliteAggregateInfoReset(Parse *pParse){
................................................................................
** Return 0 on success.  If there are problems, leave an error message
** in pParse and return non-zero.
*/
static int fillInColumnList(Parse *pParse, Select *p){
  int i, j, k;
  IdList *pTabList;
  ExprList *pEList;


  if( p==0 || p->pSrc==0 ) return 1;
  pTabList = p->pSrc;
  pEList = p->pEList;

  /* Look up every table in the table list.
  */
................................................................................
  for(i=0; i<pTabList->nId; i++){
    if( pTabList->a[i].pTab ){
      /* This routine has run before!  No need to continue */
      return 0;
    }
    if( pTabList->a[i].zName==0 ){
      /* A sub-query in the FROM clause of a SELECT */
      Table *pTab;
      assert( pTabList->a[i].pSelect!=0 );
      pTabList->a[i].pTab = pTab = 
        sqliteResultSetOfSelect(pParse, pTabList->a[i].zAlias,
                                        pTabList->a[i].pSelect);
      if( pTab==0 ){
        return 1;
      }
      pTab->isTransient = 1;
    }else{
      /* An ordinary table name in the FROM clause */

      pTabList->a[i].pTab = sqliteFindTable(pParse->db, pTabList->a[i].zName);
      if( pTabList->a[i].pTab==0 ){
        sqliteSetString(&pParse->zErrMsg, "no such table: ", 
           pTabList->a[i].zName, 0);
        pParse->nErr++;
        return 1;
      }



    }
  }

  /* For every "*" that occurs in the column list, insert the names of
  ** all columns in all tables.  The parser inserted a special expression
  ** with the TK_ALL operator for each "*" that it found in the column list.
  ** The following code just has to locate the TK_ALL expressions and expand
................................................................................
  pEList = pSelect->pEList;
  for(i=0; i<pOrderBy->nExpr; i++){
    Expr *pE = pOrderBy->a[i].pExpr;
    int match = 0;
    if( pOrderBy->a[i].done ) continue;
    for(j=0; j<pEList->nExpr; j++){
      if( pEList->a[j].zName && (pE->op==TK_ID || pE->op==TK_STRING) ){

        char *zName = pEList->a[j].zName;

        char *zLabel = sqliteStrNDup(pE->token.z, pE->token.n);
        sqliteDequote(zLabel);
        if( sqliteStrICmp(zName, zLabel)==0 ){ 
          match = 1; 
        }
        sqliteFree(zLabel);
      }
      if( match==0 && sqliteExprCompare(pE, pEList->a[j].pExpr) ){
................................................................................
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto select_end;

  /* Generate code for all sub-queries in the FROM clause
  */
  for(i=0; i<pTabList->nId; i++){
    int oldNTab;
    Table *pTab = pTabList->a[i].pTab;
    if( !pTab->isTransient ) continue;
    assert( pTabList->a[i].pSelect!=0 );
    oldNTab = pParse->nTab;
    pParse->nTab += i+1;
    sqliteVdbeAddOp(v, OP_OpenTemp, oldNTab+i, 0);
    sqliteSelect(pParse, pTabList->a[i].pSelect, SRT_Table, oldNTab+i);
    pParse->nTab = oldNTab;
  }

**    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 SELECT statements in SQLite.
**
** $Id: select.c,v 1.65 2002/02/23 02:32:10 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/
................................................................................
  sqliteExprListDelete(p->pEList);
  sqliteIdListDelete(p->pSrc);
  sqliteExprDelete(p->pWhere);
  sqliteExprListDelete(p->pGroupBy);
  sqliteExprDelete(p->pHaving);
  sqliteExprListDelete(p->pOrderBy);
  sqliteSelectDelete(p->pPrior);
  sqliteFree(p->zSelect);
  sqliteFree(p);
}

/*
** Delete the aggregate information from the parse structure.
*/
static void sqliteAggregateInfoReset(Parse *pParse){
................................................................................
** Return 0 on success.  If there are problems, leave an error message
** in pParse and return non-zero.
*/
static int fillInColumnList(Parse *pParse, Select *p){
  int i, j, k;
  IdList *pTabList;
  ExprList *pEList;
  Table *pTab;

  if( p==0 || p->pSrc==0 ) return 1;
  pTabList = p->pSrc;
  pEList = p->pEList;

  /* Look up every table in the table list.
  */
................................................................................
  for(i=0; i<pTabList->nId; i++){
    if( pTabList->a[i].pTab ){
      /* This routine has run before!  No need to continue */
      return 0;
    }
    if( pTabList->a[i].zName==0 ){
      /* A sub-query in the FROM clause of a SELECT */

      assert( pTabList->a[i].pSelect!=0 );
      pTabList->a[i].pTab = pTab = 
        sqliteResultSetOfSelect(pParse, pTabList->a[i].zAlias,
                                        pTabList->a[i].pSelect);
      if( pTab==0 ){
        return 1;
      }
      pTab->isTransient = 1;
    }else{
      /* An ordinary table or view name in the FROM clause */
      pTabList->a[i].pTab = pTab = 
        sqliteFindTable(pParse->db, pTabList->a[i].zName);
      if( pTab==0 ){
        sqliteSetString(&pParse->zErrMsg, "no such table: ", 
           pTabList->a[i].zName, 0);
        pParse->nErr++;
        return 1;
      }
      if( pTab->pSelect ){
        pTabList->a[i].pSelect = pTab->pSelect;
      }
    }
  }

  /* For every "*" that occurs in the column list, insert the names of
  ** all columns in all tables.  The parser inserted a special expression
  ** with the TK_ALL operator for each "*" that it found in the column list.
  ** The following code just has to locate the TK_ALL expressions and expand
................................................................................
  pEList = pSelect->pEList;
  for(i=0; i<pOrderBy->nExpr; i++){
    Expr *pE = pOrderBy->a[i].pExpr;
    int match = 0;
    if( pOrderBy->a[i].done ) continue;
    for(j=0; j<pEList->nExpr; j++){
      if( pEList->a[j].zName && (pE->op==TK_ID || pE->op==TK_STRING) ){
        char *zName, *zLabel;
        zName = pEList->a[j].zName;
        assert( pE->token.z );
        zLabel = sqliteStrNDup(pE->token.z, pE->token.n);
        sqliteDequote(zLabel);
        if( sqliteStrICmp(zName, zLabel)==0 ){ 
          match = 1; 
        }
        sqliteFree(zLabel);
      }
      if( match==0 && sqliteExprCompare(pE, pEList->a[j].pExpr) ){
................................................................................
  v = sqliteGetVdbe(pParse);
  if( v==0 ) goto select_end;

  /* Generate code for all sub-queries in the FROM clause
  */
  for(i=0; i<pTabList->nId; i++){
    int oldNTab;


    if( pTabList->a[i].pSelect==0 ) continue;
    oldNTab = pParse->nTab;
    pParse->nTab += i+1;
    sqliteVdbeAddOp(v, OP_OpenTemp, oldNTab+i, 0);
    sqliteSelect(pParse, pTabList->a[i].pSelect, SRT_Table, oldNTab+i);
    pParse->nTab = oldNTab;
  }

**    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 1.89 2002/02/21 12:01:27 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
................................................................................
struct Table {
  char *zName;     /* Name of the table */
  int nCol;        /* Number of columns in this table */
  Column *aCol;    /* Information about each column */
  int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
  Index *pIndex;   /* List of SQL indexes on this table. */
  int tnum;        /* Root BTree node for this table (see note above) */

  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 */
};
................................................................................
  int nLevel;          /* Number of nested loop */
  WhereLevel a[1];     /* Information about each nest loop in the WHERE */
};

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.








*/
struct Select {
  int isDistinct;        /* True if the DISTINCT keyword is present */
  ExprList *pEList;      /* The fields of the result */
  IdList *pSrc;          /* The FROM clause */
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  int op;                /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
  Select *pPrior;        /* Prior select in a compound select statement */
  int nLimit, nOffset;   /* LIMIT and OFFSET values.  -1 means not used */

};

/*
** The results of a select can be distributed in several ways.
*/
#define SRT_Callback     1  /* Invoke a callback with each row of result */
#define SRT_Mem          2  /* Store result in a memory cell */
................................................................................
void sqliteStartTable(Parse*,Token*,Token*,int);
void sqliteAddColumn(Parse*,Token*);
void sqliteAddNotNull(Parse*, int);
void sqliteAddPrimaryKey(Parse*, IdList*, int);
void sqliteAddColumnType(Parse*,Token*,Token*);
void sqliteAddDefaultValue(Parse*,Token*,int);
void sqliteEndTable(Parse*,Token*,Select*);

void sqliteDropTable(Parse*, Token*);
void sqliteDeleteTable(sqlite*, Table*);
void sqliteInsert(Parse*, Token*, ExprList*, Select*, IdList*, int);
IdList *sqliteIdListAppend(IdList*, Token*);
void sqliteIdListAddAlias(IdList*, Token*);
void sqliteIdListDelete(IdList*);
void sqliteCreateIndex(Parse*, Token*, Token*, IdList*, int, Token*, Token*);
void sqliteDropIndex(Parse*, Token*);
int sqliteSelect(Parse*, Select*, int, int);
Select *sqliteSelectNew(ExprList*,IdList*,Expr*,ExprList*,Expr*,ExprList*,
                        int,int,int);
void sqliteSelectDelete(Select*);


void sqliteDeleteFrom(Parse*, Token*, Expr*);
void sqliteUpdate(Parse*, Token*, ExprList*, Expr*, int);
WhereInfo *sqliteWhereBegin(Parse*, IdList*, Expr*, int);
void sqliteWhereEnd(WhereInfo*);
void sqliteExprCode(Parse*, Expr*);
void sqliteExprIfTrue(Parse*, Expr*, int);
void sqliteExprIfFalse(Parse*, Expr*, int);
Table *sqliteFindTable(sqlite*,char*);
Index *sqliteFindIndex(sqlite*,char*);
void sqliteUnlinkAndDeleteIndex(sqlite*,Index*);
void sqliteCopy(Parse*, Token*, Token*, Token*, int);
void sqliteVacuum(Parse*, Token*);
int sqliteGlobCompare(const unsigned char*,const unsigned char*);
int sqliteLikeCompare(const unsigned char*,const unsigned char*);
char *sqliteTableNameFromToken(Token*);
int sqliteExprCheck(Parse*, Expr*, int, int*);
................................................................................
void sqliteGenerateRowDelete(Vdbe*, Table*, int);
void sqliteGenerateRowIndexDelete(Vdbe*, Table*, int, char*);
void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
void sqliteBeginWriteOperation(Parse*);
void sqliteBeginMultiWriteOperation(Parse*);
void sqliteEndWriteOperation(Parse*);

**    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 1.90 2002/02/23 02:32:10 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
................................................................................
struct Table {
  char *zName;     /* Name of the table */
  int nCol;        /* Number of columns in this table */
  Column *aCol;    /* Information about each column */
  int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
  Index *pIndex;   /* List of SQL indexes on this table. */
  int tnum;        /* Root BTree node for this table (see note above) */
  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 */
};
................................................................................
  int nLevel;          /* Number of nested loop */
  WhereLevel a[1];     /* Information about each nest loop in the WHERE */
};

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** The zSelect field is used when the Select structure must be persistent.
** Normally, the expression tree points to tokens in the original input
** string that encodes the select.  But if the Select structure must live
** longer than its input string (for example when it is used to describe
** a VIEW) we have to make a copy of the input string so that the nodes
** of the expression tree will have something to point to.  zSelect is used
** to hold that copy.
*/
struct Select {
  int isDistinct;        /* True if the DISTINCT keyword is present */
  ExprList *pEList;      /* The fields of the result */
  IdList *pSrc;          /* The FROM clause */
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  int op;                /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
  Select *pPrior;        /* Prior select in a compound select statement */
  int nLimit, nOffset;   /* LIMIT and OFFSET values.  -1 means not used */
  char *zSelect;         /* Complete text of the SELECT command */
};

/*
** The results of a select can be distributed in several ways.
*/
#define SRT_Callback     1  /* Invoke a callback with each row of result */
#define SRT_Mem          2  /* Store result in a memory cell */
................................................................................
void sqliteStartTable(Parse*,Token*,Token*,int);
void sqliteAddColumn(Parse*,Token*);
void sqliteAddNotNull(Parse*, int);
void sqliteAddPrimaryKey(Parse*, IdList*, int);
void sqliteAddColumnType(Parse*,Token*,Token*);
void sqliteAddDefaultValue(Parse*,Token*,int);
void sqliteEndTable(Parse*,Token*,Select*);
void sqliteCreateView(Parse*,Token*,Token*,Select*);
void sqliteDropTable(Parse*, Token*);
void sqliteDeleteTable(sqlite*, Table*);
void sqliteInsert(Parse*, Token*, ExprList*, Select*, IdList*, int);
IdList *sqliteIdListAppend(IdList*, Token*);
void sqliteIdListAddAlias(IdList*, Token*);
void sqliteIdListDelete(IdList*);
void sqliteCreateIndex(Parse*, Token*, Token*, IdList*, int, Token*, Token*);
void sqliteDropIndex(Parse*, Token*);
int sqliteSelect(Parse*, Select*, int, int);
Select *sqliteSelectNew(ExprList*,IdList*,Expr*,ExprList*,Expr*,ExprList*,
                        int,int,int);
void sqliteSelectDelete(Select*);
Table *sqliteTableNameToTable(Parse*, const char*);
IdList *sqliteTableTokenToIdList(Parse*, Token*);
void sqliteDeleteFrom(Parse*, Token*, Expr*);
void sqliteUpdate(Parse*, Token*, ExprList*, Expr*, int);
WhereInfo *sqliteWhereBegin(Parse*, IdList*, Expr*, int);
void sqliteWhereEnd(WhereInfo*);
void sqliteExprCode(Parse*, Expr*);
void sqliteExprIfTrue(Parse*, Expr*, int);
void sqliteExprIfFalse(Parse*, Expr*, int);
Table *sqliteFindTable(sqlite*,const char*);
Index *sqliteFindIndex(sqlite*,const char*);
void sqliteUnlinkAndDeleteIndex(sqlite*,Index*);
void sqliteCopy(Parse*, Token*, Token*, Token*, int);
void sqliteVacuum(Parse*, Token*);
int sqliteGlobCompare(const unsigned char*,const unsigned char*);
int sqliteLikeCompare(const unsigned char*,const unsigned char*);
char *sqliteTableNameFromToken(Token*);
int sqliteExprCheck(Parse*, Expr*, int, int*);
................................................................................
void sqliteGenerateRowDelete(Vdbe*, Table*, int);
void sqliteGenerateRowIndexDelete(Vdbe*, Table*, int, char*);
void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
void sqliteBeginWriteOperation(Parse*);
void sqliteBeginMultiWriteOperation(Parse*);
void sqliteEndWriteOperation(Parse*);
void sqliteExprMoveStrings(Expr*, int);
void sqliteExprListMoveStrings(ExprList*, int);
void sqliteSelectMoveStrings(Select*, int);

*************************************************************************
** 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 1.37 2002/02/21 12:01:27 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*
................................................................................
  { "TRANSACTION",       0, TK_TRANSACTION,      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 },

  { "WHERE",             0, TK_WHERE,            0 },
};

/*
** This is the hash table
*/
#define KEY_HASH_SIZE 71
................................................................................
        }else if( pParse->rc!=SQLITE_OK ){
          sqliteSetString(pzErrMsg, sqlite_error_string(pParse->rc), 0);
          nErr++;
        }
        break;
    }
  }
  if( nErr==0 && (db->flags & SQLITE_Interrupt)==0 ){
    sqliteParser(pEngine, 0, pParse->sLastToken, pParse);
    if( pParse->zErrMsg && pParse->sErrToken.z ){
       sqliteSetNString(pzErrMsg, "near \"", -1, 
          pParse->sErrToken.z, pParse->sErrToken.n,
          "\": ", -1,
          pParse->zErrMsg, -1,
          0);

*************************************************************************
** 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 1.38 2002/02/23 02:32:10 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*
................................................................................
  { "TRANSACTION",       0, TK_TRANSACTION,      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 },
  { "WHERE",             0, TK_WHERE,            0 },
};

/*
** This is the hash table
*/
#define KEY_HASH_SIZE 71
................................................................................
        }else if( pParse->rc!=SQLITE_OK ){
          sqliteSetString(pzErrMsg, sqlite_error_string(pParse->rc), 0);
          nErr++;
        }
        break;
    }
  }
  if( zSql[i]==0 ){
    sqliteParser(pEngine, 0, pParse->sLastToken, pParse);
    if( pParse->zErrMsg && pParse->sErrToken.z ){
       sqliteSetNString(pzErrMsg, "near \"", -1, 
          pParse->sErrToken.z, pParse->sErrToken.n,
          "\": ", -1,
          pParse->zErrMsg, -1,
          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 UPDATE statements.
**
** $Id: update.c,v 1.33 2002/02/02 18:49:21 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(
................................................................................
  db = pParse->db;

  /* 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 = sqliteIdListAppend(0, pTableName);
  if( pTabList==0 ) goto update_cleanup;
  for(i=0; i<pTabList->nId; i++){
    pTabList->a[i].pTab = sqliteFindTable(db, pTabList->a[i].zName);
    if( pTabList->a[i].pTab==0 ){
      sqliteSetString(&pParse->zErrMsg, "no such table: ", 
         pTabList->a[i].zName, 0);
      pParse->nErr++;
      goto update_cleanup;
    }
    if( pTabList->a[i].pTab->readOnly ){
      sqliteSetString(&pParse->zErrMsg, "table ", pTabList->a[i].zName,
        " may not be modified", 0);
      pParse->nErr++;
      goto update_cleanup;
    }
  }
  pTab = pTabList->a[0].pTab;
  aXRef = sqliteMalloc( sizeof(int) * pTab->nCol );
  if( aXRef==0 ) goto update_cleanup;
  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;

  /* Resolve the column names in all the expressions in both the
  ** WHERE clause and in the new values.  Also find the column index

**    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 1.34 2002/02/23 02:32:10 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(
................................................................................
  db = pParse->db;

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

  /* Resolve the column names in all the expressions in both the
  ** WHERE clause and in the new values.  Also find the column index

**    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 1.36 2002/02/18 22:49:59 drh 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.
................................................................................
  /* Open all tables in the pTabList and all indices used by those tables.
  */
  for(i=0; i<pTabList->nId; i++){
    int openOp;
    Table *pTab;

    pTab = pTabList->a[i].pTab;
    if( pTab->isTransient ) continue;
    openOp = pTab->isTemp ? OP_OpenAux : OP_Open;
    sqliteVdbeAddOp(v, openOp, base+i, pTab->tnum);
    sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
    if( i==0 && !pParse->schemaVerified &&
          (pParse->db->flags & SQLITE_InTrans)==0 ){
      sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
      pParse->schemaVerified = 1;

**    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 1.37 2002/02/23 02:32:10 drh 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.
................................................................................
  /* Open all tables in the pTabList and all indices used by those tables.
  */
  for(i=0; i<pTabList->nId; i++){
    int openOp;
    Table *pTab;

    pTab = pTabList->a[i].pTab;
    if( pTab->isTransient || pTab->pSelect ) continue;
    openOp = pTab->isTemp ? OP_OpenAux : OP_Open;
    sqliteVdbeAddOp(v, openOp, base+i, pTab->tnum);
    sqliteVdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
    if( i==0 && !pParse->schemaVerified &&
          (pParse->db->flags & SQLITE_InTrans)==0 ){
      sqliteVdbeAddOp(v, OP_VerifyCookie, pParse->db->schema_cookie, 0);
      pParse->schemaVerified = 1;