database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-08 03:22:21 +03:00
Code Activity
Files
3fc190cc3fc88d712662581ac9c5e041d8b62c1b
sqlite/src/expr.c
drh 3fc190cc3f All tests now pass. But there are still issues. For example, inserts 
are way too slow.  And additional tests are needed for new features. (CVS 243)

FossilOrigin-Name: e7b65e37fd88c4d69c89cfe73ab345b8b645ada6
2001-09-14 03:24:23 +00:00

1005 lines
30 KiB
C
Raw Blame History

/*
** Copyright (c) 1999, 2000 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public
** License as published by the Free Software Foundation; either
** version 2 of the License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** General Public License for more details.
**
** You should have received a copy of the GNU General Public
** License along with this library; if not, write to the
** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
** Boston, MA 02111-1307, USA.
**
** Author contact information:
** drh@hwaci.com
** http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions.
**
** $Id: expr.c,v 1.27 2001/09/14 03:24:25 drh Exp $
*/
#include "sqliteInt.h"
/*
** Walk an expression tree. Return 1 if the expression is constant
** and 0 if it involves variables.
*/
static int isConstant(Expr *p){
switch( p->op ){
case TK_ID:
case TK_COLUMN:
case TK_DOT:
return 0;
default: {
if( p->pLeft && !isConstant(p->pLeft) ) return 0;
if( p->pRight && !isConstant(p->pRight) ) return 0;
if( p->pList ){
int i;
for(i=0; i<p->pList->nExpr; i++){
if( !isConstant(p->pList->a[i].pExpr) ) return 0;
}
}
break;
}
}
return 1;
}
/*
** Walk the expression tree and process operators of the form:
**
** expr IN (SELECT ...)
**
** These operators have to be processed before column names are
** resolved because each such operator increments pParse->nTab
** to reserve cursor numbers for its own use. But pParse->nTab
** needs to be constant once we begin resolving column names.
**
** Actually, the processing of IN-SELECT is only started by this
** routine. This routine allocates a cursor number to the IN-SELECT
** and then moves on. The code generation is done by
** sqliteExprResolveIds() which must be called afterwards.
*/
void sqliteExprResolveInSelect(Parse *pParse, Expr *pExpr){
if( pExpr==0 ) return;
if( pExpr->op==TK_IN && pExpr->pSelect!=0 ){
pExpr->iTable = pParse->nTab++;
}else{
if( pExpr->pLeft ) sqliteExprResolveInSelect(pParse, pExpr->pLeft);
if( pExpr->pRight ) sqliteExprResolveInSelect(pParse, pExpr->pRight);
if( pExpr->pList ){
int i;
ExprList *pList = pExpr->pList;
for(i=0; i<pList->nExpr; i++){
sqliteExprResolveInSelect(pParse, pList->a[i].pExpr);
}
}
}
}
/*
** Return TRUE if the given string is a row-id column name.
*/
static int sqliteIsRowid(const char *z){
if( sqliteStrICmp(z, "_ROWID_")==0 ) return 1;
if( sqliteStrICmp(z, "ROWID")==0 ) return 1;
if( sqliteStrICmp(z, "OID")==0 ) return 1;
return 0;
}
/*
** This routine walks an expression tree and resolves references to
** table columns. Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a column offset. The opcode
** for such nodes is changed to TK_COLUMN. The iTable value is changed
** to the index of the referenced table in pTabList plus the pParse->nTab
** value. The iColumn value is changed to the index of the column of the
** referenced table.
**
** We also check for instances of the IN operator. IN comes in two
** forms:
**
** expr IN (exprlist)
** and
** expr IN (SELECT ...)
**
** The first form is handled by creating a set holding the list
** of allowed values. The second form causes the SELECT to generate
** a temporary table.
**
** This routine also looks for scalar SELECTs that are part of an expression.
** If it finds any, it generates code to write the value of that select
** into a memory cell.
**
** Unknown columns or tables provoke an error. The function returns
** the number of errors seen and leaves an error message on pParse->zErrMsg.
*/
int sqliteExprResolveIds(Parse *pParse, IdList *pTabList, Expr *pExpr){
if( pExpr==0 || pTabList==0 ) return 0;
switch( pExpr->op ){
/* A lone identifier */
case TK_ID: {
int cnt = 0; /* Number of matches */
int i; /* Loop counter */
char *z = sqliteStrNDup(pExpr->token.z, pExpr->token.n);
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++){
if( sqliteStrICmp(pTab->aCol[j].zName, z)==0 ){
cnt++;
pExpr->iTable = i + pParse->nTab;
pExpr->iColumn = j;
}
}
}
if( cnt==0 && sqliteIsRowid(z) ){
pExpr->iColumn = -1;
pExpr->iTable = pParse->nTab;
cnt = 1 + (pTabList->nId>1);
}
sqliteFree(z);
if( cnt==0 ){
sqliteSetNString(&pParse->zErrMsg, "no such column: ", -1,
pExpr->token.z, pExpr->token.n, 0);
pParse->nErr++;
return 1;
}else if( cnt>1 ){
sqliteSetNString(&pParse->zErrMsg, "ambiguous column name: ", -1,
pExpr->token.z, pExpr->token.n, 0);
pParse->nErr++;
return 1;
}
pExpr->op = TK_COLUMN;
break;
}
/* A table name and column name: ID.ID */
case TK_DOT: {
int cnt = 0; /* Number of matches */
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;
}
sqliteDequote(zLeft);
sqliteDequote(zRight);
pExpr->iTable = -1;
for(i=0; i<pTabList->nId; i++){
int j;
char *zTab;
Table *pTab = pTabList->a[i].pTab;
if( pTab==0 ) continue;
if( pTabList->a[i].zAlias ){
zTab = pTabList->a[i].zAlias;
}else{
zTab = pTab->zName;
}
if( sqliteStrICmp(zTab, zLeft)!=0 ) continue;
if( 0==(cntTab++) ) pExpr->iTable = i + pParse->nTab;
for(j=0; j<pTab->nCol; j++){
if( sqliteStrICmp(pTab->aCol[j].zName, zRight)==0 ){
cnt++;
pExpr->iTable = i + pParse->nTab;
pExpr->iColumn = j;
}
}
}
if( cnt==0 && cntTab==1 && sqliteIsRowid(zRight) ){
cnt = 1;
pExpr->iColumn = -1;
}
sqliteFree(zLeft);
sqliteFree(zRight);
if( cnt==0 ){
sqliteSetNString(&pParse->zErrMsg, "no such column: ", -1,
pLeft->token.z, pLeft->token.n, ".", 1,
pRight->token.z, pRight->token.n, 0);
pParse->nErr++;
return 1;
}else if( cnt>1 ){
sqliteSetNString(&pParse->zErrMsg, "ambiguous column name: ", -1,
pLeft->token.z, pLeft->token.n, ".", 1,
pRight->token.z, pRight->token.n, 0);
pParse->nErr++;
return 1;
}
sqliteExprDelete(pLeft);
pExpr->pLeft = 0;
sqliteExprDelete(pRight);
pExpr->pRight = 0;
pExpr->op = TK_COLUMN;
break;
}
case TK_IN: {
Vdbe *v = sqliteGetVdbe(pParse);
if( v==0 ) return 1;
if( sqliteExprResolveIds(pParse, pTabList, pExpr->pLeft) ){
return 1;
}
if( pExpr->pSelect ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into a temporary
** table. The cursor number of the temporary table has already
** been put in iTable by sqliteExprResolveInSelect().
*/
sqliteVdbeAddOp(v, OP_OpenTemp, pExpr->iTable, 0, 0, 0);
if( sqliteSelect(pParse, pExpr->pSelect, SRT_Set, pExpr->iTable) );
}else if( pExpr->pList ){
/* Case 2: expr IN (exprlist)
**
** Create a set to put the exprlist values in. The Set id is stored
** in iTable.
*/
int i, iSet;
for(i=0; i<pExpr->pList->nExpr; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
if( !isConstant(pE2) ){
sqliteSetString(&pParse->zErrMsg,
"right-hand side of IN operator must be constant", 0);
pParse->nErr++;
return 1;
}
if( sqliteExprCheck(pParse, pE2, 0, 0) ){
return 1;
}
}
iSet = pExpr->iTable = pParse->nSet++;
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, 0, 0);
sqliteVdbeChangeP3(v, addr, pE2->token.z, pE2->token.n);
sqliteVdbeDequoteP3(v, addr);
break;
}
default: {
sqliteExprCode(pParse, pE2);
sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0, 0, 0);
break;
}
}
}
}
break;
}
case TK_SELECT: {
/* This has to be a scalar SELECT. Generate code to put the
** value of this select in a memory cell and record the number
** of the memory cell in iColumn.
*/
pExpr->iColumn = pParse->nMem++;
if( sqliteSelect(pParse, pExpr->pSelect, SRT_Mem, pExpr->iColumn) ){
return 1;
}
break;
}
/* For all else, just recursively walk the tree */
default: {
if( pExpr->pLeft
&& sqliteExprResolveIds(pParse, pTabList, pExpr->pLeft) ){
return 1;
}
if( pExpr->pRight
&& sqliteExprResolveIds(pParse, pTabList, pExpr->pRight) ){
return 1;
}
if( pExpr->pList ){
int i;
ExprList *pList = pExpr->pList;
for(i=0; i<pList->nExpr; i++){
if( sqliteExprResolveIds(pParse, pTabList, pList->a[i].pExpr) ){
return 1;
}
}
}
}
}
return 0;
}
#if 0 /* NOT USED */
/*
** Compare a token against a string. Return TRUE if they match.
*/
static int sqliteTokenCmp(Token *pToken, const char *zStr){
int n = strlen(zStr);
if( n!=pToken->n ) return 0;
return sqliteStrNICmp(pToken->z, zStr, n)==0;
}
#endif
/*
** Convert a function name into its integer identifier. Return the
** identifier. Return FN_Unknown if the function name is unknown.
*/
int sqliteFuncId(Token *pToken){
static const struct {
char *zName;
int len;
int id;
} aFunc[] = {
{ "count", 5, FN_Count },
{ "min", 3, FN_Min },
{ "max", 3, FN_Max },
{ "sum", 3, FN_Sum },
{ "avg", 3, FN_Avg },
{ "fcnt", 4, FN_Fcnt }, /* Used for testing only */
{ "length", 6, FN_Length},
{ "substr", 6, FN_Substr},
};
int i;
for(i=0; i<ArraySize(aFunc); i++){
if( aFunc[i].len==pToken->n
&& sqliteStrNICmp(pToken->z, aFunc[i].zName, aFunc[i].len)==0 ){
return aFunc[i].id;
}
}
return FN_Unknown;
}
/*
** Error check the functions in an expression. Make sure all
** function names are recognized and all functions have the correct
** number of arguments. Leave an error message in pParse->zErrMsg
** if anything is amiss. Return the number of errors.
**
** if pIsAgg is not null and this expression is an aggregate function
** (like count(*) or max(value)) then write a 1 into *pIsAgg.
*/
int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int nErr = 0;
if( pExpr==0 ) return 0;
switch( pExpr->op ){
case TK_FUNCTION: {
int id = sqliteFuncId(&pExpr->token);
int n = pExpr->pList ? pExpr->pList->nExpr : 0;
int no_such_func = 0;
int too_many_args = 0;
int too_few_args = 0;
int is_agg = 0;
int i;
pExpr->iColumn = id;
switch( id ){
case FN_Unknown: {
no_such_func = 1;
break;
}
case FN_Count: {
no_such_func = !allowAgg;
too_many_args = n>1;
is_agg = 1;
break;
}
case FN_Max:
case FN_Min: {
too_few_args = allowAgg ? n<1 : n<2;
is_agg = n==1;
break;
}
case FN_Avg:
case FN_Sum: {
no_such_func = !allowAgg;
too_many_args = n>1;
too_few_args = n<1;
is_agg = 1;
break;
}
case FN_Length: {
too_few_args = n<1;
too_many_args = n>1;
break;
}
case FN_Substr: {
too_few_args = n<3;
too_many_args = n>3;
break;
}
/* The "fcnt(*)" function always returns the number of fetch
** operations that have occurred so far while processing the
** SQL statement. This information can be used by test procedures
** to verify that indices are being used properly to minimize
** searching. All arguments to fcnt() are ignored. fcnt() has
** no use (other than testing) that we are aware of.
*/
case FN_Fcnt: {
n = 0;
break;
}
default: break;
}
if( no_such_func ){
sqliteSetNString(&pParse->zErrMsg, "no such function: ", -1,
pExpr->token.z, pExpr->token.n, 0);
pParse->nErr++;
nErr++;
}else if( too_many_args ){
sqliteSetNString(&pParse->zErrMsg, "too many arguments to function ",-1,
pExpr->token.z, pExpr->token.n, "()", 2, 0);
pParse->nErr++;
nErr++;
}else if( too_few_args ){
sqliteSetNString(&pParse->zErrMsg, "too few arguments to function ",-1,
pExpr->token.z, pExpr->token.n, "()", 2, 0);
pParse->nErr++;
nErr++;
}
if( is_agg ) pExpr->op = TK_AGG_FUNCTION;
if( is_agg && pIsAgg ) *pIsAgg = 1;
for(i=0; nErr==0 && i<n; i++){
nErr = sqliteExprCheck(pParse, pExpr->pList->a[i].pExpr,
allowAgg && !is_agg, pIsAgg);
}
}
default: {
if( pExpr->pLeft ){
nErr = sqliteExprCheck(pParse, pExpr->pLeft, allowAgg, pIsAgg);
}
if( nErr==0 && pExpr->pRight ){
nErr = sqliteExprCheck(pParse, pExpr->pRight, allowAgg, pIsAgg);
}
if( nErr==0 && pExpr->pList ){
int n = pExpr->pList->nExpr;
int i;
for(i=0; nErr==0 && i<n; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
nErr = sqliteExprCheck(pParse, pE2, allowAgg, pIsAgg);
}
}
break;
}
}
return nErr;
}
/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
*/
void sqliteExprCode(Parse *pParse, Expr *pExpr){
Vdbe *v = pParse->pVdbe;
int op;
if( v==0 || pExpr==0 ) return;
switch( pExpr->op ){
case TK_PLUS: op = OP_Add; break;
case TK_MINUS: op = OP_Subtract; break;
case TK_STAR: op = OP_Multiply; break;
case TK_SLASH: op = OP_Divide; break;
case TK_AND: op = OP_And; break;
case TK_OR: op = OP_Or; break;
case TK_LT: op = OP_Lt; break;
case TK_LE: op = OP_Le; break;
case TK_GT: op = OP_Gt; break;
case TK_GE: op = OP_Ge; break;
case TK_NE: op = OP_Ne; break;
case TK_EQ: op = OP_Eq; break;
case TK_LIKE: op = OP_Like; break;
case TK_GLOB: op = OP_Glob; break;
case TK_ISNULL: op = OP_IsNull; break;
case TK_NOTNULL: op = OP_NotNull; break;
case TK_NOT: op = OP_Not; break;
case TK_UMINUS: op = OP_Negative; break;
default: break;
}
switch( pExpr->op ){
case TK_COLUMN: {
if( pParse->useAgg ){
sqliteVdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg, 0, 0);
}else if( pExpr->iColumn>=0 ){
sqliteVdbeAddOp(v, OP_Column, pExpr->iTable, pExpr->iColumn, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_Recno, pExpr->iTable, 0, 0, 0);
}
break;
}
case TK_INTEGER: {
int i = atoi(pExpr->token.z);
sqliteVdbeAddOp(v, OP_Integer, i, 0, 0, 0);
break;
}
case TK_FLOAT: {
int addr = sqliteVdbeAddOp(v, OP_String, 0, 0, 0, 0);
sqliteVdbeChangeP3(v, addr, pExpr->token.z, pExpr->token.n);
break;
}
case TK_STRING: {
int addr = sqliteVdbeAddOp(v, OP_String, 0, 0, 0, 0);
sqliteVdbeChangeP3(v, addr, pExpr->token.z, pExpr->token.n);
sqliteVdbeDequoteP3(v, addr);
break;
}
case TK_NULL: {
sqliteVdbeAddOp(v, OP_Null, 0, 0, 0, 0);
break;
}
case TK_AND:
case TK_OR:
case TK_PLUS:
case TK_STAR:
case TK_MINUS:
case TK_SLASH: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
sqliteVdbeAddOp(v, op, 0, 0, 0, 0);
break;
}
case TK_CONCAT: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
sqliteVdbeAddOp(v, OP_Concat, 2, 0, 0, 0);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ:
case TK_LIKE:
case TK_GLOB: {
int dest;
sqliteVdbeAddOp(v, OP_Integer, 1, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
dest = sqliteVdbeCurrentAddr(v) + 2;
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
sqliteVdbeAddOp(v, OP_AddImm, -1, 0, 0, 0);
break;
}
case TK_UMINUS: {
assert( pExpr->pLeft );
if( pExpr->pLeft->op==TK_INTEGER ){
int i = atoi(pExpr->pLeft->token.z);
sqliteVdbeAddOp(v, OP_Integer, -i, 0, 0, 0);
break;
}else if( pExpr->pLeft->op==TK_FLOAT ){
Token *p = &pExpr->pLeft->token;
char *z = sqliteMalloc( p->n + 2 );
sprintf(z, "-%.*s", p->n, p->z);
sqliteVdbeAddOp(v, OP_String, 0, 0, z, 0);
sqliteFree(z);
break;
}
/* Fall through into TK_NOT */
}
case TK_NOT: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, op, 0, 0, 0, 0);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
int dest;
sqliteVdbeAddOp(v, OP_Integer, 1, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pLeft);
dest = sqliteVdbeCurrentAddr(v) + 2;
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
sqliteVdbeAddOp(v, OP_AddImm, -1, 0, 0, 0);
break;
}
case TK_AGG_FUNCTION: {
sqliteVdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg, 0, 0);
if( pExpr->iColumn==FN_Avg ){
assert( pParse->iAggCount>=0 && pParse->iAggCount<pParse->nAgg );
sqliteVdbeAddOp(v, OP_AggGet, 0, pParse->iAggCount, 0, 0);
sqliteVdbeAddOp(v, OP_Divide, 0, 0, 0, 0);
}
break;
}
case TK_FUNCTION: {
int id = pExpr->iColumn;
int op;
int i;
ExprList *pList = pExpr->pList;
switch( id ){
case FN_Fcnt: {
sqliteVdbeAddOp(v, OP_Fcnt, 0, 0, 0, 0);
break;
}
case FN_Min:
case FN_Max: {
op = id==FN_Min ? OP_Min : OP_Max;
for(i=0; i<pList->nExpr; i++){
sqliteExprCode(pParse, pList->a[i].pExpr);
if( i>0 ){
sqliteVdbeAddOp(v, op, 0, 0, 0, 0);
}
}
break;
}
case FN_Length: {
sqliteExprCode(pParse, pList->a[0].pExpr);
sqliteVdbeAddOp(v, OP_Strlen, 0, 0, 0, 0);
break;
}
case FN_Substr: {
for(i=0; i<pList->nExpr; i++){
sqliteExprCode(pParse, pList->a[i].pExpr);
}
sqliteVdbeAddOp(v, OP_Substr, 0, 0, 0, 0);
break;
}
default: {
/* Can't happen! */
break;
}
}
break;
}
case TK_SELECT: {
sqliteVdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0, 0, 0);
break;
}
case TK_IN: {
int addr;
sqliteVdbeAddOp(v, OP_Integer, 1, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pLeft);
addr = sqliteVdbeCurrentAddr(v);
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, addr+2, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, addr+2, 0, 0);
}
sqliteVdbeAddOp(v, OP_AddImm, -1, 0, 0, 0);
break;
}
case TK_BETWEEN: {
int lbl = sqliteVdbeMakeLabel(v);
sqliteVdbeAddOp(v, OP_Integer, 0, 0, 0, 0);
sqliteExprIfFalse(pParse, pExpr, lbl);
sqliteVdbeAddOp(v, OP_AddImm, 1, 0, 0, 0);
sqliteVdbeResolveLabel(v, lbl);
break;
}
}
return;
}
/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
*/
void sqliteExprIfTrue(Parse *pParse, Expr *pExpr, int dest){
Vdbe *v = pParse->pVdbe;
int op = 0;
if( v==0 || pExpr==0 ) return;
switch( pExpr->op ){
case TK_LT: op = OP_Lt; break;
case TK_LE: op = OP_Le; break;
case TK_GT: op = OP_Gt; break;
case TK_GE: op = OP_Ge; break;
case TK_NE: op = OP_Ne; break;
case TK_EQ: op = OP_Eq; break;
case TK_LIKE: op = OP_Like; break;
case TK_GLOB: op = OP_Glob; break;
case TK_ISNULL: op = OP_IsNull; break;
case TK_NOTNULL: op = OP_NotNull; break;
default: break;
}
switch( pExpr->op ){
case TK_AND: {
int d2 = sqliteVdbeMakeLabel(v);
sqliteExprIfFalse(pParse, pExpr->pLeft, d2);
sqliteExprIfTrue(pParse, pExpr->pRight, dest);
sqliteVdbeResolveLabel(v, d2);
break;
}
case TK_OR: {
sqliteExprIfTrue(pParse, pExpr->pLeft, dest);
sqliteExprIfTrue(pParse, pExpr->pRight, dest);
break;
}
case TK_NOT: {
sqliteExprIfFalse(pParse, pExpr->pLeft, dest);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ:
case TK_LIKE:
case TK_GLOB: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_IN: {
sqliteExprCode(pParse, pExpr->pLeft);
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, dest, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, dest, 0, 0);
}
break;
}
case TK_BETWEEN: {
int lbl = sqliteVdbeMakeLabel(v);
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
sqliteVdbeAddOp(v, OP_Lt, 0, lbl, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
sqliteVdbeAddOp(v, OP_Le, 0, dest, 0, 0);
sqliteVdbeAddOp(v, OP_Integer, 0, 0, 0, 0);
sqliteVdbeAddOp(v, OP_Pop, 1, 0, 0, lbl);
break;
}
default: {
sqliteExprCode(pParse, pExpr);
sqliteVdbeAddOp(v, OP_If, 0, dest, 0, 0);
break;
}
}
}
/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is false but execution
** continues straight thru if the expression is true.
*/
void sqliteExprIfFalse(Parse *pParse, Expr *pExpr, int dest){
Vdbe *v = pParse->pVdbe;
int op = 0;
if( v==0 || pExpr==0 ) return;
switch( pExpr->op ){
case TK_LT: op = OP_Ge; break;
case TK_LE: op = OP_Gt; break;
case TK_GT: op = OP_Le; break;
case TK_GE: op = OP_Lt; break;
case TK_NE: op = OP_Eq; break;
case TK_EQ: op = OP_Ne; break;
case TK_LIKE: op = OP_Like; break;
case TK_GLOB: op = OP_Glob; break;
case TK_ISNULL: op = OP_NotNull; break;
case TK_NOTNULL: op = OP_IsNull; break;
default: break;
}
switch( pExpr->op ){
case TK_AND: {
sqliteExprIfFalse(pParse, pExpr->pLeft, dest);
sqliteExprIfFalse(pParse, pExpr->pRight, dest);
break;
}
case TK_OR: {
int d2 = sqliteVdbeMakeLabel(v);
sqliteExprIfTrue(pParse, pExpr->pLeft, d2);
sqliteExprIfFalse(pParse, pExpr->pRight, dest);
sqliteVdbeResolveLabel(v, d2);
break;
}
case TK_NOT: {
sqliteExprIfTrue(pParse, pExpr->pLeft, dest);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_LIKE:
case TK_GLOB: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteExprCode(pParse, pExpr->pRight);
sqliteVdbeAddOp(v, op, 1, dest, 0, 0);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, op, 0, dest, 0, 0);
break;
}
case TK_IN: {
sqliteExprCode(pParse, pExpr->pLeft);
if( pExpr->pSelect ){
sqliteVdbeAddOp(v, OP_NotFound, pExpr->iTable, dest, 0, 0);
}else{
sqliteVdbeAddOp(v, OP_SetNotFound, pExpr->iTable, dest, 0, 0);
}
break;
}
case TK_BETWEEN: {
int addr;
sqliteExprCode(pParse, pExpr->pLeft);
sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
addr = sqliteVdbeCurrentAddr(v);
sqliteVdbeAddOp(v, OP_Ge, 0, addr+3, 0, 0);
sqliteVdbeAddOp(v, OP_Pop, 1, 0, 0, 0);
sqliteVdbeAddOp(v, OP_Goto, 0, dest, 0, 0);
sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
sqliteVdbeAddOp(v, OP_Gt, 0, dest, 0, 0);
break;
}
default: {
sqliteExprCode(pParse, pExpr);
sqliteVdbeAddOp(v, OP_Not, 0, 0, 0, 0);
sqliteVdbeAddOp(v, OP_If, 0, dest, 0, 0);
break;
}
}
}
/*
** Do a deep comparison of two expression trees. Return TRUE (non-zero)
** if they are identical and return FALSE if they differ in any way.
*/
int sqliteExprCompare(Expr *pA, Expr *pB){
int i;
if( pA==0 ){
return pB==0;
}else if( pB==0 ){
return 0;
}
if( pA->op!=pB->op ) return 0;
if( !sqliteExprCompare(pA->pLeft, pB->pLeft) ) return 0;
if( !sqliteExprCompare(pA->pRight, pB->pRight) ) return 0;
if( pA->pList ){
if( pB->pList==0 ) return 0;
if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
for(i=0; i<pA->pList->nExpr; i++){
if( !sqliteExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
return 0;
}
}
}else if( pB->pList ){
return 0;
}
if( pA->pSelect || pB->pSelect ) return 0;
if( pA->token.z ){
if( pB->token.z==0 ) return 0;
if( pB->token.n!=pA->token.n ) return 0;
if( sqliteStrNICmp(pA->token.z, pB->token.z, pA->token.n)!=0 ) return 0;
}
return 1;
}
/*
** Add a new element to the pParse->aAgg[] array and return its index.
*/
static int appendAggInfo(Parse *pParse){
if( (pParse->nAgg & 0x7)==0 ){
int amt = pParse->nAgg + 8;
pParse->aAgg = sqliteRealloc(pParse->aAgg, amt*sizeof(pParse->aAgg[0]));
if( pParse->aAgg==0 ){
pParse->nAgg = 0;
return -1;
}
}
memset(&pParse->aAgg[pParse->nAgg], 0, sizeof(pParse->aAgg[0]));
return pParse->nAgg++;
}
/*
** Analyze the given expression looking for aggregate functions and
** for variables that need to be added to the pParse->aAgg[] array.
** Make additional entries to the pParse->aAgg[] array as necessary.
**
** This routine should only be called after the expression has been
** analyzed by sqliteExprResolveIds() and sqliteExprCheck().
**
** If errors are seen, leave an error message in zErrMsg and return
** the number of errors.
*/
int sqliteExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
int i;
AggExpr *aAgg;
int nErr = 0;
if( pExpr==0 ) return 0;
switch( pExpr->op ){
case TK_COLUMN: {
aAgg = pParse->aAgg;
for(i=0; i<pParse->nAgg; i++){
if( aAgg[i].isAgg ) continue;
if( aAgg[i].pExpr->iTable==pExpr->iTable
&& aAgg[i].pExpr->iColumn==pExpr->iColumn ){
break;
}
}
if( i>=pParse->nAgg ){
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 0;
pParse->aAgg[i].pExpr = pExpr;
}
pExpr->iAgg = i;
break;
}
case TK_AGG_FUNCTION: {
if( pExpr->iColumn==FN_Count || pExpr->iColumn==FN_Avg ){
if( pParse->iAggCount>=0 ){
i = pParse->iAggCount;
}else{
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = 0;
pParse->iAggCount = i;
}
if( pExpr->iColumn==FN_Count ){
pExpr->iAgg = i;
break;
}
}
aAgg = pParse->aAgg;
for(i=0; i<pParse->nAgg; i++){
if( !aAgg[i].isAgg ) continue;
if( sqliteExprCompare(aAgg[i].pExpr, pExpr) ){
break;
}
}
if( i>=pParse->nAgg ){
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = pExpr;
}
pExpr->iAgg = i;
break;
}
default: {
if( pExpr->pLeft ){
nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pLeft);
}
if( nErr==0 && pExpr->pRight ){
nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pRight);
}
if( nErr==0 && pExpr->pList ){
int n = pExpr->pList->nExpr;
int i;
for(i=0; nErr==0 && i<n; i++){
nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pList->a[i].pExpr);
}
}
break;
}
}
return nErr;
}
View Git Blame Copy Permalink