SQLite

**    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 1.184 2005/01/20 13:03:10 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

      break;
    }
    case TK_CTIMESTAMP: {
      *pzName = "current_timestamp";
      *pnName = 17;
      break;
    }





  }
}

/*
** This routine is designed as an xFunc for walkExprTree().
**
** Resolve symbolic names into TK_COLUMN operators for the current

    case TK_STRING: {
      assert( TK_FLOAT==OP_Real );
      assert( TK_STRING==OP_String8 );
      sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z, pExpr->token.n);
      sqlite3VdbeDequoteP3(v, -1);
      break;
    }
#ifndef SQLITE_OMIT_BLOB_LITERAL
    case TK_BLOB: {
      assert( TK_BLOB==OP_HexBlob );
      sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z+1, pExpr->token.n-1);
      sqlite3VdbeDequoteP3(v, -1);
      break;
    }
#endif
    case TK_NULL: {
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      break;
    }
    case TK_VARIABLE: {
      sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
      if( pExpr->token.n>1 ){

        sqlite3ExprCode(pParse, pExpr->pRight);
      }else{
        sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      }
      sqlite3VdbeResolveLabel(v, expr_end_label);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      if( !pParse->trigStack ){
        sqlite3ErrorMsg(pParse,
                       "RAISE() may only be used within a trigger-program");
	return;
      }
      if( pExpr->iColumn!=OE_Ignore ){
         assert( pExpr->iColumn==OE_Rollback ||
                 pExpr->iColumn == OE_Abort ||
                 pExpr->iColumn == OE_Fail );
         sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
                        pExpr->token.z, pExpr->token.n);
         sqlite3VdbeDequoteP3(v, -1);
      } else {
         assert( pExpr->iColumn == OE_Ignore );
         sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
         sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
         VdbeComment((v, "# raise(IGNORE)"));
      }
    }
#endif
    break;
  }
}

/*
** Generate code that evalutes the given expression and leaves the result
** on the stack.  See also sqlite3ExprCode().

**    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 1.230 2005/01/20 13:03:10 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.

    sqlite3VdbeAddOp(v, OP_PutStrKey, distinct, 0);
    if( pOrderBy==0 ){
      codeLimiter(v, p, iContinue, iBreak, nColumn);
    }
  }

  switch( eDest ){
#ifndef SQLITE_OMIT_COMPOUND_SELECT
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
    case SRT_Union: {
      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);
      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      sqlite3VdbeAddOp(v, OP_PutStrKey, iParm, 0);
      break;
    }

    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);
      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
      break;
    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_TempTable: {
      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
      if( pOrderBy ){
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        sqlite3VdbeAddOp(v, OP_NewRecno, iParm, 0);
        sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
        sqlite3VdbeAddOp(v, OP_PutIntKey, iParm, 0);
      }
      break;
    }














    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
    ** item into the set table with bogus data.
    */
    case SRT_Set: {
      int addr1 = sqlite3VdbeCurrentAddr(v);
      int addr2;

*/
static const char *columnType(Parse *pParse, SrcList *pTabList, Expr *pExpr){
  char const *zType;
  int j;
  if( pExpr==0 || pTabList==0 ) return 0;

  sqlite3ExprResolveNames(pParse, pTabList, 0, 0, pExpr, 1, 0);

  /* The TK_AS operator can only occur in ORDER BY, GROUP BY, HAVING,
  ** and LIMIT clauses.  But pExpr originates in the result set of a
  ** SELECT.  So pExpr can never contain an AS operator.
  */
  assert( pExpr->op!=TK_AS );

  switch( pExpr->op ){
    case TK_COLUMN: {
      Table *pTab;
      int iCol = pExpr->iColumn;
      for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable; j++){}
      assert( j<pTabList->nSrc );
      pTab = pTabList->a[j].pTab;

      break;
    }
    case TK_SELECT: {
      Select *pS = pExpr->pSelect;
      zType = columnType(pParse, pS->pSrc, pS->pEList->a[0].pExpr); 
      break;
    }







    default:
      zType = 0;
  }
  
  return zType;
}

  ExprList *pEList    /* Expressions defining the result set */
){
  Vdbe *v = pParse->pVdbe;
  int i, j;
  sqlite3 *db = pParse->db;
  int fullNames, shortNames;

#ifdef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  assert( v!=0 );
  if( pParse->colNamesSet || v==0 || sqlite3_malloc_failed ) return;
  pParse->colNamesSet = 1;
  fullNames = (db->flags & SQLITE_FullColNames)!=0;
  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);

** This routine is called on the Select structure that defines a
** VIEW in order to undo any bindings to tables.  This is necessary
** because those tables might be DROPed by a subsequent SQL command.
** If the bindings are not removed, then the Select.pSrc->a[].pTab field
** will be left pointing to a deallocated Table structure after the
** DROP and a coredump will occur the next time the VIEW is used.
*/
#if 0
void sqlite3SelectUnbind(Select *p){
  int i;
  SrcList *pSrc = p->pSrc;
  struct SrcList_item *pItem;
  Table *pTab;
  if( p==0 ) return;
  for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
    if( (pTab = pItem->pTab)!=0 ){
      if( pTab->isTransient ){
        sqlite3DeleteTable(0, pTab);
      }
      pItem->pTab = 0;
      if( pItem->pSelect ){
        sqlite3SelectUnbind(pItem->pSelect);
      }
    }
  }
}
#endif

/*
** This routine associates entries in an ORDER BY expression list with
** columns in a result.  For each ORDER BY expression, the opcode of
** the top-level node is changed to TK_COLUMN and the iColumn value of
** the top-level node is filled in with column number and the iTable
** value of the top-level node is filled with iTable parameter.