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gerrit.openfyde.cn / chromium.googlesource.com / chromium / deps / sqlite / 31ef3b91f5009f184e209ca7ddc4b009f59ecc56 / . / src / expr.c
blob: 7b4768f9a4d84a488bbd07d1e1b3c6521ff287fb [file] [log] [blame]
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.139 2004/06/11 10:51:27 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
char const *sqlite3AffinityString(char affinity){
switch( affinity ){
case SQLITE_AFF_INTEGER: return "i";
case SQLITE_AFF_NUMERIC: return "n";
case SQLITE_AFF_TEXT: return "t";
case SQLITE_AFF_NONE: return "o";
default:
assert(0);
}
}
/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expresssions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
if( pExpr->op==TK_AS ){
return sqlite3ExprAffinity(pExpr->pLeft);
}
if( pExpr->op==TK_SELECT ){
return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
}
return pExpr->affinity;
}
/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
CollSeq *pColl = 0;
if( pExpr ){
pColl = pExpr->pColl;
if( pExpr->op==TK_AS && !pColl ){
return sqlite3ExprCollSeq(pParse, pExpr->pLeft);
}
}
if( sqlite3CheckCollSeq(pParse, pColl) ){
pColl = 0;
}
return pColl;
}
/*
** pExpr is the left operand of a comparison operator. aff2 is the
** type affinity of the right operand. This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
char aff1 = sqlite3ExprAffinity(pExpr);
if( aff1 && aff2 ){
/* Both sides of the comparison are columns. If one has numeric or
** integer affinity, use that. Otherwise use no affinity.
*/
if( aff1==SQLITE_AFF_INTEGER || aff2==SQLITE_AFF_INTEGER ){
return SQLITE_AFF_INTEGER;
}else if( aff1==SQLITE_AFF_NUMERIC || aff2==SQLITE_AFF_NUMERIC ){
return SQLITE_AFF_NUMERIC;
}else{
return SQLITE_AFF_NONE;
}
}else if( !aff1 && !aff2 ){
/* Neither side of the comparison is a column. Use numeric affinity
** for the comparison.
*/
return SQLITE_AFF_NUMERIC;
}else{
/* One side is a column, the other is not. Use the columns affinity. */
return (aff1 + aff2);
}
}
/*
** pExpr is a comparison operator. Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(Expr *pExpr){
char aff;
assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
pExpr->op==TK_NE );
assert( pExpr->pLeft );
aff = sqlite3ExprAffinity(pExpr->pLeft);
if( pExpr->pRight ){
aff = sqlite3CompareAffinity(pExpr->pRight, aff);
}
else if( pExpr->pSelect ){
aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
}
else if( !aff ){
aff = SQLITE_AFF_NUMERIC;
}
return aff;
}
/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
char aff = comparisonAffinity(pExpr);
return
(aff==SQLITE_AFF_NONE) ||
(aff==SQLITE_AFF_NUMERIC && idx_affinity==SQLITE_AFF_INTEGER) ||
(aff==SQLITE_AFF_INTEGER && idx_affinity==SQLITE_AFF_NUMERIC) ||
(aff==idx_affinity);
}
/*
** Return the P1 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
** If jumpIfNull is true, then set the low byte of the returned
** P1 value to tell the opcode to jump if either expression
** evaluates to NULL.
*/
static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
char aff = sqlite3ExprAffinity(pExpr2);
return (((int)sqlite3CompareAffinity(pExpr1, aff))<<8)+(jumpIfNull?1:0);
}
/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
*/
static CollSeq* binaryCompareCollSeq(Parse *pParse, Expr *pLeft, Expr *pRight){
CollSeq *pColl = sqlite3ExprCollSeq(pParse, pLeft);
if( !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pRight);
}
return pColl;
}
/*
** 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 *sqlite3Expr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
Expr *pNew;
pNew = sqliteMalloc( sizeof(Expr) );
if( pNew==0 ){
/* When malloc fails, we leak memory from pLeft and pRight */
return 0;
}
pNew->op = op;
pNew->pLeft = pLeft;
pNew->pRight = pRight;
if( pToken ){
assert( pToken->dyn==0 );
pNew->token = *pToken;
pNew->span = *pToken;
}else{
assert( pNew->token.dyn==0 );
assert( pNew->token.z==0 );
assert( pNew->token.n==0 );
if( pLeft && pRight ){
sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
}else{
pNew->span = pNew->token;
}
}
return pNew;
}
/*
** Set the Expr.span field of the given expression to span all
** text between the two given tokens.
*/
void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
assert( pRight!=0 );
assert( pLeft!=0 );
/* Note: pExpr might be NULL due to a prior malloc failure */
if( pExpr && pRight->z && pLeft->z ){
if( pLeft->dyn==0 && pRight->dyn==0 ){
pExpr->span.z = pLeft->z;
pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
}else{
pExpr->span.z = 0;
}
}
}
/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(ExprList *pList, Token *pToken){
Expr *pNew;
pNew = sqliteMalloc( sizeof(Expr) );
if( pNew==0 ){
/* sqlite3ExprListDelete(pList); // Leak pList when malloc fails */
return 0;
}
pNew->op = TK_FUNCTION;
pNew->pList = pList;
if( pToken ){
assert( pToken->dyn==0 );
pNew->token = *pToken;
}else{
pNew->token.z = 0;
}
pNew->span = pNew->token;
return pNew;
}
/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(Expr *p){
if( p==0 ) return;
if( p->span.dyn ) sqliteFree((char*)p->span.z);
if( p->token.dyn ) sqliteFree((char*)p->token.z);
sqlite3ExprDelete(p->pLeft);
sqlite3ExprDelete(p->pRight);
sqlite3ExprListDelete(p->pList);
sqlite3SelectDelete(p->pSelect);
sqliteFree(p);
}
/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements. The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** The expression list, ID, and source lists return by sqlite3ExprListDup(),
** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
** by subsequent calls to sqlite*ListAppend() routines.
**
** Any tables that the SrcList might point to are not duplicated.
*/
Expr *sqlite3ExprDup(Expr *p){
Expr *pNew;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*p) );
if( pNew==0 ) return 0;
memcpy(pNew, p, sizeof(*pNew));
if( p->token.z!=0 ){
pNew->token.z = sqliteStrDup(p->token.z);
pNew->token.dyn = 1;
}else{
assert( pNew->token.z==0 );
}
pNew->span.z = 0;
pNew->pLeft = sqlite3ExprDup(p->pLeft);
pNew->pRight = sqlite3ExprDup(p->pRight);
pNew->pList = sqlite3ExprListDup(p->pList);
pNew->pSelect = sqlite3SelectDup(p->pSelect);
return pNew;
}
void sqlite3TokenCopy(Token *pTo, Token *pFrom){
if( pTo->dyn ) sqliteFree((char*)pTo->z);
if( pFrom->z ){
pTo->n = pFrom->n;
pTo->z = sqliteStrNDup(pFrom->z, pFrom->n);
pTo->dyn = 1;
}else{
pTo->z = 0;
}
}
ExprList *sqlite3ExprListDup(ExprList *p){
ExprList *pNew;
struct ExprList_item *pItem;
int i;
if( p==0 ) return 0;
pNew = sqliteMalloc( sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nExpr = pNew->nAlloc = p->nExpr;
pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
if( pItem==0 ) return 0; /* Leaks memory after a malloc failure */
for(i=0; i<p->nExpr; i++, pItem++){
Expr *pNewExpr, *pOldExpr;
pItem->pExpr = pNewExpr = sqlite3ExprDup(pOldExpr = p->a[i].pExpr);
if( pOldExpr->span.z!=0 && pNewExpr ){
/* Always make a copy of the span for top-level expressions in the
** expression list. The logic in SELECT processing that determines
** the names of columns in the result set needs this information */
sqlite3TokenCopy(&pNewExpr->span, &pOldExpr->span);
}
assert( pNewExpr==0 || pNewExpr->span.z!=0
|| pOldExpr->span.z==0 || sqlite3_malloc_failed );
pItem->zName = sqliteStrDup(p->a[i].zName);
pItem->sortOrder = p->a[i].sortOrder;
pItem->isAgg = p->a[i].isAgg;
pItem->done = 0;
}
return pNew;
}
SrcList *sqlite3SrcListDup(SrcList *p){
SrcList *pNew;
int i;
int nByte;
if( p==0 ) return 0;
nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
pNew = sqliteMallocRaw( nByte );
if( pNew==0 ) return 0;
pNew->nSrc = pNew->nAlloc = p->nSrc;
for(i=0; i<p->nSrc; i++){
struct SrcList_item *pNewItem = &pNew->a[i];
struct SrcList_item *pOldItem = &p->a[i];
pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase);
pNewItem->zName = sqliteStrDup(pOldItem->zName);
pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
pNewItem->jointype = pOldItem->jointype;
pNewItem->iCursor = pOldItem->iCursor;
pNewItem->pTab = 0;
pNewItem->pSelect = sqlite3SelectDup(pOldItem->pSelect);
pNewItem->pOn = sqlite3ExprDup(pOldItem->pOn);
pNewItem->pUsing = sqlite3IdListDup(pOldItem->pUsing);
}
return pNew;
}
IdList *sqlite3IdListDup(IdList *p){
IdList *pNew;
int i;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*pNew) );
if( pNew==0 ) return 0;
pNew->nId = pNew->nAlloc = p->nId;
pNew->a = sqliteMallocRaw( p->nId*sizeof(p->a[0]) );
if( pNew->a==0 ) return 0;
for(i=0; i<p->nId; i++){
struct IdList_item *pNewItem = &pNew->a[i];
struct IdList_item *pOldItem = &p->a[i];
pNewItem->zName = sqliteStrDup(pOldItem->zName);
pNewItem->idx = pOldItem->idx;
}
return pNew;
}
Select *sqlite3SelectDup(Select *p){
Select *pNew;
if( p==0 ) return 0;
pNew = sqliteMallocRaw( sizeof(*p) );
if( pNew==0 ) return 0;
pNew->isDistinct = p->isDistinct;
pNew->pEList = sqlite3ExprListDup(p->pEList);
pNew->pSrc = sqlite3SrcListDup(p->pSrc);
pNew->pWhere = sqlite3ExprDup(p->pWhere);
pNew->pGroupBy = sqlite3ExprListDup(p->pGroupBy);
pNew->pHaving = sqlite3ExprDup(p->pHaving);
pNew->pOrderBy = sqlite3ExprListDup(p->pOrderBy);
pNew->op = p->op;
pNew->pPrior = sqlite3SelectDup(p->pPrior);
pNew->nLimit = p->nLimit;
pNew->nOffset = p->nOffset;
pNew->zSelect = 0;
pNew->iLimit = -1;
pNew->iOffset = -1;
pNew->ppOpenTemp = 0;
return pNew;
}
/*
** Add a new element to the end of an expression list. If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqlite3ExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
if( pList==0 ){
pList = sqliteMalloc( sizeof(ExprList) );
if( pList==0 ){
/* sqlite3ExprDelete(pExpr); // Leak memory if malloc fails */
return 0;
}
assert( pList->nAlloc==0 );
}
if( pList->nAlloc<=pList->nExpr ){
pList->nAlloc = pList->nAlloc*2 + 4;
pList->a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]));
if( pList->a==0 ){
/* sqlite3ExprDelete(pExpr); // Leak memory if malloc fails */
pList->nExpr = pList->nAlloc = 0;
return pList;
}
}
assert( pList->a!=0 );
if( pExpr || pName ){
struct ExprList_item *pItem = &pList->a[pList->nExpr++];
memset(pItem, 0, sizeof(*pItem));
pItem->pExpr = pExpr;
if( pName ){
sqlite3SetNString(&pItem->zName, pName->z, pName->n, 0);
sqlite3Dequote(pItem->zName);
}
}
return pList;
}
/*
** Delete an entire expression list.
*/
void sqlite3ExprListDelete(ExprList *pList){
int i;
if( pList==0 ) return;
assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
assert( pList->nExpr<=pList->nAlloc );
for(i=0; i<pList->nExpr; i++){
sqlite3ExprDelete(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.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
switch( p->op ){
case TK_ID:
case TK_COLUMN:
case TK_DOT:
case TK_FUNCTION:
return 0;
case TK_NULL:
case TK_STRING:
case TK_BLOB:
case TK_INTEGER:
case TK_FLOAT:
case TK_VARIABLE:
return 1;
default: {
if( p->pLeft && !sqlite3ExprIsConstant(p->pLeft) ) return 0;
if( p->pRight && !sqlite3ExprIsConstant(p->pRight) ) return 0;
if( p->pList ){
int i;
for(i=0; i<p->pList->nExpr; i++){
if( !sqlite3ExprIsConstant(p->pList->a[i].pExpr) ) return 0;
}
}
return p->pLeft!=0 || p->pRight!=0 || (p->pList && p->pList->nExpr>0);
}
}
return 0;
}
/*
** If the given expression codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue. If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
switch( p->op ){
case TK_INTEGER: {
if( sqlite3GetInt32(p->token.z, pValue) ){
return 1;
}
break;
}
case TK_STRING: {
const char *z = p->token.z;
int n = p->token.n;
if( n>0 && z[0]=='-' ){ z++; n--; }
while( n>0 && *z && isdigit(*z) ){ z++; n--; }
if( n==0 && sqlite3GetInt32(p->token.z, pValue) ){
return 1;
}
break;
}
case TK_UPLUS: {
return sqlite3ExprIsInteger(p->pLeft, pValue);
}
case TK_UMINUS: {
int v;
if( sqlite3ExprIsInteger(p->pLeft, &v) ){
*pValue = -v;
return 1;
}
break;
}
default: break;
}
return 0;
}
/*
** Return TRUE if the given string is a row-id column name.
*/
int sqlite3IsRowid(const char *z){
if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
if( sqlite3StrICmp(z, "OID")==0 ) return 1;
return 0;
}
/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column. The following changes
** are made to pExpr:
**
** pExpr->iDb Set the index in db->aDb[] of the database holding
** the table.
** pExpr->iTable Set to the cursor number for the table obtained
** from pSrcList.
** pExpr->iColumn Set to the column number within the table.
** pExpr->op Set to TK_COLUMN.
** pExpr->pLeft Any expression this points to is deleted
** pExpr->pRight Any expression this points to is deleted.
**
** The pDbToken is the name of the database (the "X"). This value may be
** NULL meaning that name is of the form Y.Z or Z. Any available database
** can be used. The pTableToken is the name of the table (the "Y"). This
** value can be NULL if pDbToken is also NULL. If pTableToken is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return non-zero. Return zero on success.
*/
static int lookupName(
Parse *pParse, /* The parsing context */
Token *pDbToken, /* Name of the database containing table, or NULL */
Token *pTableToken, /* Name of table containing column, or NULL */
Token *pColumnToken, /* Name of the column. */
SrcList *pSrcList, /* List of tables used to resolve column names */
ExprList *pEList, /* List of expressions used to resolve "AS" */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */
char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */
char *zCol = 0; /* Name of the column. The "Z" */
int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column names */
int cntTab = 0; /* Number of matching table names */
sqlite *db = pParse->db; /* The database */
assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
if( pDbToken && pDbToken->z ){
zDb = sqliteStrNDup(pDbToken->z, pDbToken->n);
sqlite3Dequote(zDb);
}else{
zDb = 0;
}
if( pTableToken && pTableToken->z ){
zTab = sqliteStrNDup(pTableToken->z, pTableToken->n);
sqlite3Dequote(zTab);
}else{
assert( zDb==0 );
zTab = 0;
}
zCol = sqliteStrNDup(pColumnToken->z, pColumnToken->n);
sqlite3Dequote(zCol);
if( sqlite3_malloc_failed ){
return 1; /* Leak memory (zDb and zTab) if malloc fails */
}
assert( zTab==0 || pEList==0 );
pExpr->iTable = -1;
for(i=0; i<pSrcList->nSrc; i++){
struct SrcList_item *pItem = &pSrcList->a[i];
Table *pTab = pItem->pTab;
Column *pCol;
if( pTab==0 ) continue;
assert( pTab->nCol>0 );
if( zTab ){
if( pItem->zAlias ){
char *zTabName = pItem->zAlias;
if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
}else{
char *zTabName = pTab->zName;
if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
if( zDb!=0 && sqlite3StrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){
continue;
}
}
}
if( 0==(cntTab++) ){
pExpr->iTable = pItem->iCursor;
pExpr->iDb = pTab->iDb;
}
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
cnt++;
pExpr->iTable = pItem->iCursor;
pExpr->iDb = pTab->iDb;
/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
pExpr->iColumn = j==pTab->iPKey ? -1 : j;
pExpr->affinity = pTab->aCol[j].affinity;
pExpr->pColl = pTab->aCol[j].pColl;
break;
}
}
}
/* If we have not already resolved the name, then maybe
** it is a new.* or old.* trigger argument reference
*/
if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
TriggerStack *pTriggerStack = pParse->trigStack;
Table *pTab = 0;
if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
pExpr->iTable = pTriggerStack->newIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab) == 0 ){
pExpr->iTable = pTriggerStack->oldIdx;
assert( pTriggerStack->pTab );
pTab = pTriggerStack->pTab;
}
if( pTab ){
int j;
Column *pCol = pTab->aCol;
pExpr->iDb = pTab->iDb;
cntTab++;
for(j=0; j < pTab->nCol; j++, pCol++) {
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
cnt++;
pExpr->iColumn = j==pTab->iPKey ? -1 : j;
pExpr->affinity = pTab->aCol[j].affinity;
pExpr->pColl = pTab->aCol[j].pColl;
break;
}
}
}
}
/*
** Perhaps the name is a reference to the ROWID
*/
if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
cnt = 1;
pExpr->iColumn = -1;
pExpr->affinity = SQLITE_AFF_INTEGER;
}
/*
** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
** might refer to an result-set alias. This happens, for example, when
** we are resolving names in the WHERE clause of the following command:
**
** SELECT a+b AS x FROM table WHERE x<10;
**
** In cases like this, replace pExpr with a copy of the expression that
** forms the result set entry ("a+b" in the example) and return immediately.
** Note that the expression in the result set should have already been
** resolved by the time the WHERE clause is resolved.
*/
if( cnt==0 && pEList!=0 ){
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zName;
if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
assert( pExpr->pLeft==0 && pExpr->pRight==0 );
pExpr->op = TK_AS;
pExpr->iColumn = j;
pExpr->pLeft = sqlite3ExprDup(pEList->a[j].pExpr);
sqliteFree(zCol);
assert( zTab==0 && zDb==0 );
return 0;
}
}
}
/*
** If X and Y are NULL (in other words if only the column name Z is
** supplied) and the value of Z is enclosed in double-quotes, then
** Z is a string literal if it doesn't match any column names. In that
** case, we need to return right away and not make any changes to
** pExpr.
*/
if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
sqliteFree(zCol);
return 0;
}
/*
** cnt==0 means there was not match. cnt>1 means there were two or
** more matches. Either way, we have an error.
*/
if( cnt!=1 ){
char *z = 0;
char *zErr;
zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
if( zDb ){
sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, 0);
}else if( zTab ){
sqlite3SetString(&z, zTab, ".", zCol, 0);
}else{
z = sqliteStrDup(zCol);
}
sqlite3ErrorMsg(pParse, zErr, z);
sqliteFree(z);
}
/* Clean up and return
*/
sqliteFree(zDb);
sqliteFree(zTab);
sqliteFree(zCol);
sqlite3ExprDelete(pExpr->pLeft);
pExpr->pLeft = 0;
sqlite3ExprDelete(pExpr->pRight);
pExpr->pRight = 0;
pExpr->op = TK_COLUMN;
sqlite3AuthRead(pParse, pExpr, pSrcList);
return cnt!=1;
}
/*
** 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
** Expr.opcode for such nodes is changed to TK_COLUMN. The Expr.iTable
** value is changed to the index of the referenced table in pTabList
** plus the "base" value. The base value will ultimately become the
** VDBE cursor number for a cursor that is pointing into the referenced
** table. The Expr.iColumn value is changed to the index of the column
** of the referenced table. The Expr.iColumn value for the special
** ROWID column is -1. Any INTEGER PRIMARY KEY column is tried as an
** alias for ROWID.
**
** 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 sqlite3ExprResolveIds(
Parse *pParse, /* The parser context */
SrcList *pSrcList, /* List of tables used to resolve column names */
ExprList *pEList, /* List of expressions used to resolve "AS" */
Expr *pExpr /* The expression to be analyzed. */
){
int i;
if( pExpr==0 || pSrcList==0 ) return 0;
for(i=0; i<pSrcList->nSrc; i++){
assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab );
}
switch( pExpr->op ){
/* Double-quoted strings (ex: "abc") are used as identifiers if
** possible. Otherwise they remain as strings. Single-quoted
** strings (ex: 'abc') are always string literals.
*/
case TK_STRING: {
if( pExpr->token.z[0]=='\'' ) break;
/* Fall thru into the TK_ID case if this is a double-quoted string */
}
/* A lone identifier is the name of a columnd.
*/
case TK_ID: {
if( lookupName(pParse, 0, 0, &pExpr->token, pSrcList, pEList, pExpr) ){
return 1;
}
break;
}
/* A table name and column name: ID.ID
** Or a database, table and column: ID.ID.ID
*/
case TK_DOT: {
Token *pColumn;
Token *pTable;
Token *pDb;
Expr *pRight;
pRight = pExpr->pRight;
if( pRight->op==TK_ID ){
pDb = 0;
pTable = &pExpr->pLeft->token;
pColumn = &pRight->token;
}else{
assert( pRight->op==TK_DOT );
pDb = &pExpr->pLeft->token;
pTable = &pRight->pLeft->token;
pColumn = &pRight->pRight->token;
}
if( lookupName(pParse, pDb, pTable, pColumn, pSrcList, 0, pExpr) ){
return 1;
}
break;
}
case TK_IN: {
char affinity;
Vdbe *v = sqlite3GetVdbe(pParse);
KeyInfo keyInfo;
int addr; /* Address of OP_OpenTemp instruction */
if( v==0 ) return 1;
if( sqlite3ExprResolveIds(pParse, pSrcList, pEList, pExpr->pLeft) ){
return 1;
}
affinity = sqlite3ExprAffinity(pExpr->pLeft);
/* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
** expression it is handled the same way. A temporary table is
** filled with single-field index keys representing the results
** from the SELECT or the <exprlist>.
**
** If the 'x' expression is a column value, or the SELECT...
** statement returns a column value, then the affinity of that
** column is used to build the index keys. If both 'x' and the
** SELECT... statement are columns, then numeric affinity is used
** if either column has NUMERIC or INTEGER affinity. If neither
** 'x' nor the SELECT... statement are columns, then numeric affinity
** is used.
*/
pExpr->iTable = pParse->nTab++;
addr = sqlite3VdbeAddOp(v, OP_OpenTemp, pExpr->iTable, 0);
memset(&keyInfo, 0, sizeof(keyInfo));
keyInfo.nField = 1;
sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);
if( pExpr->pSelect ){
/* Case 1: expr IN (SELECT ...)
**
** Generate code to write the results of the select into the temporary
** table allocated and opened above.
*/
int iParm = pExpr->iTable + (((int)affinity)<<16);
assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0);
if( pExpr->pSelect->pEList && pExpr->pSelect->pEList->nExpr>0 ){
keyInfo.aColl[0] = binaryCompareCollSeq(pParse, pExpr->pLeft,
pExpr->pSelect->pEList->a[0].pExpr);
}
}else if( pExpr->pList ){
/* Case 2: expr IN (exprlist)
**
** For each expression, build an index key from the evaluation and
** store it in the temporary table. If <expr> is a column, then use
** that columns affinity when building index keys. If <expr> is not
** a column, use numeric affinity.
*/
int i;
char const *affStr;
if( !affinity ){
affinity = SQLITE_AFF_NUMERIC;
}
affStr = sqlite3AffinityString(affinity);
keyInfo.aColl[0] = pExpr->pLeft->pColl;
/* Loop through each expression in <exprlist>. */
for(i=0; i<pExpr->pList->nExpr; i++){
Expr *pE2 = pExpr->pList->a[i].pExpr;
/* Check that the expression is constant and valid. */
if( !sqlite3ExprIsConstant(pE2) ){
sqlite3ErrorMsg(pParse,
"right-hand side of IN operator must be constant");
return 1;
}
if( sqlite3ExprCheck(pParse, pE2, 0, 0) ){
return 1;
}
/* Evaluate the expression and insert it into the temp table */
sqlite3ExprCode(pParse, pE2);
sqlite3VdbeOp3(v, OP_MakeKey, 1, 0, affStr, P3_STATIC);
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
sqlite3VdbeAddOp(v, OP_PutStrKey, pExpr->iTable, 0);
}
}
sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO);
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(sqlite3Select(pParse, pExpr->pSelect, SRT_Mem,pExpr->iColumn,0,0,0,0)){
return 1;
}
break;
}
/* For all else, just recursively walk the tree */
default: {
if( pExpr->pLeft
&& sqlite3ExprResolveIds(pParse, pSrcList, pEList, pExpr->pLeft) ){
return 1;
}
if( pExpr->pRight
&& sqlite3ExprResolveIds(pParse, pSrcList, pEList, pExpr->pRight) ){
return 1;
}
if( pExpr->pList ){
int i;
ExprList *pList = pExpr->pList;
for(i=0; i<pList->nExpr; i++){
Expr *pArg = pList->a[i].pExpr;
if( sqlite3ExprResolveIds(pParse, pSrcList, pEList, pArg) ){
return 1;
}
}
}
}
}
return 0;
}
/*
** pExpr is a node that defines a function of some kind. It might
** be a syntactic function like "count(x)" or it might be a function
** that implements an operator, like "a LIKE b".
**
** This routine makes *pzName point to the name of the function and
** *pnName hold the number of characters in the function name.
*/
static void getFunctionName(Expr *pExpr, const char **pzName, int *pnName){
switch( pExpr->op ){
case TK_FUNCTION: {
*pzName = pExpr->token.z;
*pnName = pExpr->token.n;
break;
}
case TK_LIKE: {
*pzName = "like";
*pnName = 4;
break;
}
case TK_GLOB: {
*pzName = "glob";
*pnName = 4;
break;
}
default: {
*pzName = "can't happen";
*pnName = 12;
break;
}
}
}
/*
** 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 sqlite3ExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int nErr = 0;
if( pExpr==0 ) return 0;
switch( pExpr->op ){
case TK_GLOB:
case TK_LIKE:
case TK_FUNCTION: {
int n = pExpr->pList ? pExpr->pList->nExpr : 0; /* Number of arguments */
int no_such_func = 0; /* True if no such function exists */
int wrong_num_args = 0; /* True if wrong number of arguments */
int is_agg = 0; /* True if is an aggregate function */
int i;
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef;
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
getFunctionName(pExpr, &zId, &nId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, iPrefEnc, 0);
if( pDef==0 ){
pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, iPrefEnc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
wrong_num_args = 1;
}
}else{
is_agg = pDef->xFunc==0;
}
if( is_agg && !allowAgg ){
sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId, zId);
nErr++;
is_agg = 0;
}else if( no_such_func ){
sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
nErr++;
}else if( wrong_num_args ){
sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
nId, zId);
nErr++;
}
if( is_agg ){
pExpr->op = TK_AGG_FUNCTION;
if( pIsAgg ) *pIsAgg = 1;
}
for(i=0; nErr==0 && i<n; i++){
nErr = sqlite3ExprCheck(pParse, pExpr->pList->a[i].pExpr,
allowAgg && !is_agg, pIsAgg);
}
/* FIX ME: Compute pExpr->affinity based on the expected return
** type of the function
*/
}
default: {
if( pExpr->pLeft ){
nErr = sqlite3ExprCheck(pParse, pExpr->pLeft, allowAgg, pIsAgg);
}
if( nErr==0 && pExpr->pRight ){
nErr = sqlite3ExprCheck(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 = sqlite3ExprCheck(pParse, pE2, allowAgg, pIsAgg);
}
}
break;
}
}
return nErr;
}
/*
** Return one of the SQLITE_AFF_* affinity types that indicates the likely
** data type of the result of the given expression.
**
** Not every expression has a fixed type. If the type cannot be determined
** at compile-time, then try to return the type affinity if the expression
** is a column. Otherwise just return SQLITE_AFF_NONE.
**
** The sqlite3ExprResolveIds() and sqlite3ExprCheck() routines must have
** both been called on the expression before it is passed to this routine.
*/
int sqlite3ExprType(Expr *p){
if( p==0 ) return SQLITE_AFF_NONE;
while( p ) switch( p->op ){
case TK_CONCAT:
case TK_STRING:
case TK_BLOB:
return SQLITE_AFF_TEXT;
case TK_AS:
p = p->pLeft;
break;
case TK_VARIABLE:
case TK_NULL:
return SQLITE_AFF_NONE;
case TK_SELECT: /*** FIX ME ****/
case TK_COLUMN: /*** FIX ME ****/
case TK_CASE: /*** FIX ME ****/
default:
return SQLITE_AFF_NUMERIC;
}
return SQLITE_AFF_NONE;
}
/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
*/
static void codeInteger(Vdbe *v, const char *z, int n){
int i;
if( sqlite3GetInt32(z, &i) ){
sqlite3VdbeAddOp(v, OP_Integer, i, 0);
}else if( sqlite3FitsIn64Bits(z) ){
sqlite3VdbeOp3(v, OP_Integer, 0, 0, z, n);
}else{
sqlite3VdbeOp3(v, OP_Real, 0, 0, z, n);
}
}
/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
*/
void sqlite3ExprCode(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_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;
case TK_BITAND: op = OP_BitAnd; break;
case TK_BITOR: op = OP_BitOr; break;
case TK_BITNOT: op = OP_BitNot; break;
case TK_LSHIFT: op = OP_ShiftLeft; break;
case TK_RSHIFT: op = OP_ShiftRight; break;
case TK_REM: op = OP_Remainder; break;
case TK_FLOAT: op = OP_Real; break;
case TK_STRING: op = OP_String8; break;
case TK_BLOB: op = OP_HexBlob; break;
default: break;
}
switch( pExpr->op ){
case TK_COLUMN: {
if( pParse->useAgg ){
sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
}else if( pExpr->iColumn>=0 ){
sqlite3VdbeAddOp(v, OP_Column, pExpr->iTable, pExpr->iColumn);
}else{
sqlite3VdbeAddOp(v, OP_Recno, pExpr->iTable, 0);
}
break;
}
case TK_INTEGER: {
codeInteger(v, pExpr->token.z, pExpr->token.n);
break;
}
case TK_FLOAT:
case TK_STRING: {
sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z, pExpr->token.n);
sqlite3VdbeDequoteP3(v, -1);
break;
}
case TK_BLOB: {
sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z+1, pExpr->token.n-1);
sqlite3VdbeDequoteP3(v, -1);
break;
}
case TK_NULL: {
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
break;
}
case TK_VARIABLE: {
sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
int p1 = binaryCompareP1(pExpr->pLeft, pExpr->pRight, 0);
CollSeq *p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeOp3(v, op, p1, 0, (void *)p3, P3_COLLSEQ);
break;
}
case TK_AND:
case TK_OR:
case TK_PLUS:
case TK_STAR:
case TK_MINUS:
case TK_REM:
case TK_BITAND:
case TK_BITOR:
case TK_SLASH: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeAddOp(v, op, 0, 0);
break;
}
case TK_LSHIFT:
case TK_RSHIFT: {
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 0, 0);
break;
}
case TK_CONCAT: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeAddOp(v, OP_Concat, 2, 0);
break;
}
case TK_UMINUS: {
Expr *pLeft = pExpr->pLeft;
assert( pLeft );
if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
Token *p = &pLeft->token;
char *z = sqliteMalloc( p->n + 2 );
sprintf(z, "-%.*s", p->n, p->z);
if( pLeft->op==TK_FLOAT ){
sqlite3VdbeOp3(v, OP_Real, 0, 0, z, p->n+1);
}else{
codeInteger(v, z, p->n+1);
}
sqliteFree(z);
break;
}
/* Fall through into TK_NOT */
}
case TK_BITNOT:
case TK_NOT: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 0, 0);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
int dest;
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
sqlite3ExprCode(pParse, pExpr->pLeft);
dest = sqlite3VdbeCurrentAddr(v) + 2;
sqlite3VdbeAddOp(v, op, 1, dest);
sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
}
break;
case TK_AGG_FUNCTION: {
sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
break;
}
case TK_GLOB:
case TK_LIKE:
case TK_FUNCTION: {
ExprList *pList = pExpr->pList;
int nExpr = pList ? pList->nExpr : 0;
FuncDef *pDef;
int nId;
const char *zId;
int p2 = 0;
int i;
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
CollSeq *pColl = 0;
getFunctionName(pExpr, &zId, &nId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, iPrefEnc, 0);
assert( pDef!=0 );
nExpr = sqlite3ExprCodeExprList(pParse, pList);
for(i=0; i<nExpr && i<32; i++){
if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
p2 |= (1<<i);
}
if( pDef->needCollSeq && !pColl ){
pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
}
}
if( pDef->needCollSeq ){
if( !pColl ) pColl = pParse->db->pDfltColl;
sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, pColl, P3_COLLSEQ);
}
sqlite3VdbeOp3(v, OP_Function, nExpr, p2, (char*)pDef, P3_FUNCDEF);
break;
}
case TK_SELECT: {
sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
break;
}
case TK_IN: {
int addr;
char const *affStr;
/* Figure out the affinity to use to create a key from the results
** of the expression. affinityStr stores a static string suitable for
** P3 of OP_MakeKey.
*/
affStr = sqlite3AffinityString(comparisonAffinity(pExpr));
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
/* Code the <expr> from "<expr> IN (...)". The temporary table
** pExpr->iTable contains the values that make up the (...) set.
*/
sqlite3ExprCode(pParse, pExpr->pLeft);
addr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4); /* addr + 0 */
sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
sqlite3VdbeAddOp(v, OP_Goto, 0, addr+7);
sqlite3VdbeOp3(v, OP_MakeKey, 1, 0, affStr, P3_STATIC); /* addr + 4 */
sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, addr+7);
sqlite3VdbeAddOp(v, OP_AddImm, -1, 0); /* addr + 6 */
break;
}
case TK_BETWEEN: {
int p1;
CollSeq *p3;
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pExpr->pList->a[0].pExpr);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[0].pExpr, 0);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[0].pExpr);
sqlite3VdbeOp3(v, OP_Ge, p1, 0, (void *)p3, P3_COLLSEQ);
sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
sqlite3ExprCode(pParse, pExpr->pList->a[1].pExpr);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[1].pExpr, 0);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[1].pExpr);
sqlite3VdbeOp3(v, OP_Le, p1, 0, (void *)p3, P3_COLLSEQ);
sqlite3VdbeAddOp(v, OP_And, 0, 0);
break;
}
case TK_UPLUS:
case TK_AS: {
sqlite3ExprCode(pParse, pExpr->pLeft);
break;
}
case TK_CASE: {
int expr_end_label;
int jumpInst;
int addr;
int nExpr;
int i;
assert(pExpr->pList);
assert((pExpr->pList->nExpr % 2) == 0);
assert(pExpr->pList->nExpr > 0);
nExpr = pExpr->pList->nExpr;
expr_end_label = sqlite3VdbeMakeLabel(v);
if( pExpr->pLeft ){
sqlite3ExprCode(pParse, pExpr->pLeft);
}
for(i=0; i<nExpr; i=i+2){
sqlite3ExprCode(pParse, pExpr->pList->a[i].pExpr);
if( pExpr->pLeft ){
int p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[i].pExpr, 1);
CollSeq *p3 = binaryCompareCollSeq(pParse, pExpr->pLeft,
pExpr->pList->a[i].pExpr);
sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
jumpInst = sqlite3VdbeOp3(v, OP_Ne, p1, 0, (void *)p3, P3_COLLSEQ);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
}else{
jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
}
sqlite3ExprCode(pParse, pExpr->pList->a[i+1].pExpr);
sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
addr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeChangeP2(v, jumpInst, addr);
}
if( pExpr->pLeft ){
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
}
if( pExpr->pRight ){
sqlite3ExprCode(pParse, pExpr->pRight);
}else{
sqlite3VdbeAddOp(v, OP_String8, 0, 0);
}
sqlite3VdbeResolveLabel(v, expr_end_label);
break;
}
case TK_RAISE: {
if( !pParse->trigStack ){
sqlite3ErrorMsg(pParse,
"RAISE() may only be used within a trigger-program");
pParse->nErr++;
return;
}
if( 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 );
sqlite3VdbeOp3(v, OP_Goto, 0, pParse->trigStack->ignoreJump,
"(IGNORE jump)", 0);
}
}
break;
}
}
/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
** Return the number of elements pushed onto the stack.
*/
int sqlite3ExprCodeExprList(
Parse *pParse, /* Parsing context */
ExprList *pList /* The expression list to be coded */
){
struct ExprList_item *pItem;
int i, n;
Vdbe *v;
if( pList==0 ) return 0;
v = sqlite3GetVdbe(pParse);
n = pList->nExpr;
for(pItem=pList->a, i=0; i<n; i++, pItem++){
sqlite3ExprCode(pParse, pItem->pExpr);
}
return n;
}
/*
** 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.
**
** If the expression evaluates to NULL (neither true nor false), then
** take the jump if the jumpIfNull flag is true.
*/
void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
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_ISNULL: op = OP_IsNull; break;
case TK_NOTNULL: op = OP_NotNull; break;
default: break;
}
switch( pExpr->op ){
case TK_AND: {
int d2 = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
break;
}
case TK_OR: {
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
break;
}
case TK_NOT: {
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
int p1 = binaryCompareP1(pExpr->pLeft, pExpr->pRight, jumpIfNull);
CollSeq *p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeOp3(v, op, p1, dest, (void *)p3, P3_COLLSEQ);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 1, dest);
break;
}
case TK_BETWEEN: {
/* The expression "x BETWEEN y AND z" is implemented as:
**
** 1 IF (x < y) GOTO 3
** 2 IF (x <= z) GOTO <dest>
** 3 ...
*/
int addr;
int p1;
CollSeq *p3;
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pExpr->pList->a[0].pExpr);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[0].pExpr, !jumpIfNull);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[0].pExpr);
addr = sqlite3VdbeOp3(v, OP_Lt, p1, 0, (void *)p3, P3_COLLSEQ);
sqlite3ExprCode(pParse, pExpr->pList->a[1].pExpr);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[1].pExpr, jumpIfNull);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[1].pExpr);
sqlite3VdbeOp3(v, OP_Le, p1, dest, (void *)p3, P3_COLLSEQ);
sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
break;
}
default: {
sqlite3ExprCode(pParse, pExpr);
sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
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.
**
** If the expression evaluates to NULL (neither true nor false) then
** jump if jumpIfNull is true or fall through if jumpIfNull is false.
*/
void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
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_ISNULL: op = OP_NotNull; break;
case TK_NOTNULL: op = OP_IsNull; break;
default: break;
}
switch( pExpr->op ){
case TK_AND: {
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
break;
}
case TK_OR: {
int d2 = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
sqlite3VdbeResolveLabel(v, d2);
break;
}
case TK_NOT: {
sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
break;
}
case TK_LT:
case TK_LE:
case TK_GT:
case TK_GE:
case TK_NE:
case TK_EQ: {
int p1 = binaryCompareP1(pExpr->pLeft, pExpr->pRight, jumpIfNull);
CollSeq *p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeOp3(v, op, p1, dest, (void *)p3, P3_COLLSEQ);
break;
}
case TK_ISNULL:
case TK_NOTNULL: {
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 1, dest);
break;
}
case TK_BETWEEN: {
/* The expression is "x BETWEEN y AND z". It is implemented as:
**
** 1 IF (x >= y) GOTO 3
** 2 GOTO <dest>
** 3 IF (x > z) GOTO <dest>
*/
int addr;
int p1;
CollSeq *p3;
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
sqlite3ExprCode(pParse, pExpr->pList->a[0].pExpr);
addr = sqlite3VdbeCurrentAddr(v);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[0].pExpr, !jumpIfNull);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[0].pExpr);
sqlite3VdbeOp3(v, OP_Ge, p1, addr+3, (void *)p3, P3_COLLSEQ);
sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
sqlite3VdbeAddOp(v, OP_Goto, 0, dest);
sqlite3ExprCode(pParse, pExpr->pList->a[1].pExpr);
p1 = binaryCompareP1(pExpr->pLeft, pExpr->pList->a[1].pExpr, jumpIfNull);
p3 = binaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pList->a[1].pExpr);
sqlite3VdbeOp3(v, OP_Gt, p1, dest, (void *)p3, P3_COLLSEQ);
break;
}
default: {
sqlite3ExprCode(pParse, pExpr);
sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
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 sqlite3ExprCompare(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( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
if( !sqlite3ExprCompare(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( !sqlite3ExprCompare(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->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
if( pA->token.z ){
if( pB->token.z==0 ) return 0;
if( pB->token.n!=pA->token.n ) return 0;
if( sqlite3StrNICmp(pA->token.z, pB->token.z, pB->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;
AggExpr *aAgg = sqliteRealloc(pParse->aAgg, amt*sizeof(pParse->aAgg[0]));
if( aAgg==0 ){
return -1;
}
pParse->aAgg = aAgg;
}
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 sqlite3ExprResolveIds() and sqlite3ExprCheck().
**
** If errors are seen, leave an error message in zErrMsg and return
** the number of errors.
*/
int sqlite3ExprAnalyzeAggregates(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: {
aAgg = pParse->aAgg;
for(i=0; i<pParse->nAgg; i++){
if( !aAgg[i].isAgg ) continue;
if( sqlite3ExprCompare(aAgg[i].pExpr, pExpr) ){
break;
}
}
if( i>=pParse->nAgg ){
int iPrefEnc = (pParse->db->enc==TEXT_Utf8)?0:1;
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = pExpr;
pParse->aAgg[i].pFunc = sqlite3FindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
pExpr->pList ? pExpr->pList->nExpr : 0, iPrefEnc, 0);
}
pExpr->iAgg = i;
break;
}
default: {
if( pExpr->pLeft ){
nErr = sqlite3ExprAnalyzeAggregates(pParse, pExpr->pLeft);
}
if( nErr==0 && pExpr->pRight ){
nErr = sqlite3ExprAnalyzeAggregates(pParse, pExpr->pRight);
}
if( nErr==0 && pExpr->pList ){
int n = pExpr->pList->nExpr;
int i;
for(i=0; nErr==0 && i<n; i++){
nErr = sqlite3ExprAnalyzeAggregates(pParse, pExpr->pList->a[i].pExpr);
}
}
break;
}
}
return nErr;
}
/*
** Locate a user function given a name, a number of arguments and a flag
** indicating whether the function prefers UTF-16 over UTF-8. Return a
** pointer to the FuncDef structure that defines that function, or return
** NULL if the function does not exist.
**
** If the createFlag argument is true, then a new (blank) FuncDef
** structure is created and liked into the "db" structure if a
** no matching function previously existed. When createFlag is true
** and the nArg parameter is -1, then only a function that accepts
** any number of arguments will be returned.
**
** If createFlag is false and nArg is -1, then the first valid
** function found is returned. A function is valid if either xFunc
** or xStep is non-zero.
**
** If createFlag is false, then a function with the required name and
** number of arguments may be returned even if the eTextRep flag does not
** match that requested.
*/
FuncDef *sqlite3FindFunction(
sqlite *db, /* An open database */
const char *zName, /* Name of the function. Not null-terminated */
int nName, /* Number of characters in the name */
int nArg, /* Number of arguments. -1 means any number */
int eTextRep, /* True to retrieve UTF-16 versions. */
int createFlag /* Create new entry if true and does not otherwise exist */
){
FuncDef *p; /* Iterator variable */
FuncDef *pFirst; /* First function with this name */
FuncDef *pBest = 0; /* Best match found so far */
int matchqual = 0;
/* Normalize argument values to simplify comparisons below. */
if( eTextRep ) eTextRep = 1;
if( nArg<-1 ) nArg = -1;
pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
for(p=pFirst; p; p=p->pNext){
if( 1 || p->xFunc || p->xStep ){
if( p->nArg==nArg && p->iPrefEnc==eTextRep ){
/* A perfect match. */
pBest = p;
matchqual = 4;
break;
}
if( p->nArg==nArg ){
/* Number of arguments matches, but not the text encoding */
pBest = p;
matchqual = 3;
}
else if( (p->nArg<0) || (nArg<0) ){
if( matchqual<2 && p->iPrefEnc==eTextRep ){
/* Matched a varargs function with correct text encoding */
pBest = p;
matchqual = 2;
}
if( matchqual<1 ){
/* Matched a varargs function with incorrect text encoding */
pBest = p;
matchqual = 1;
}
}
}
}
if( createFlag && matchqual<4 &&
(pBest = sqliteMalloc(sizeof(*pBest)+nName+1)) ){
pBest->nArg = nArg;
pBest->pNext = pFirst;
pBest->zName = (char*)&pBest[1];
pBest->iPrefEnc = eTextRep;
memcpy(pBest->zName, zName, nName);
pBest->zName[nName] = 0;
sqlite3HashInsert(&db->aFunc, pBest->zName, nName, (void*)pBest);
}
if( pBest && (pBest->xStep || pBest->xFunc || createFlag) ){
return pBest;
}
return 0;
}