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Add the column_origin_name() etc. APIs. (CVS 3069)

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FossilOrigin-Name: 82f502cdc1fead3bf7e3190d5c9db3aee6919ed4
This commit is contained in:
danielk1977
2006-02-10 02:27:42 +00:00
parent 86631a5ad1
commit 955de52c9c
18 changed files with 436 additions and 137 deletions
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152
src/select.c
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@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.301 2006/01/24 12:09:19 danielk1977 Exp $
** $Id: select.c,v 1.302 2006/02/10 02:27:43 danielk1977 Exp $
*/
#include "sqliteInt.h"
@@ -762,14 +762,31 @@ static void generateSortTail(
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
**
** If the declaration type is the exact datatype definition extracted from
** the original CREATE TABLE statement if the expression is a column.
** The declaration type is the exact datatype definition extracted from the
** original CREATE TABLE statement if the expression is a column. The
** declaration type for a ROWID field is INTEGER. Exactly when an expression
** is considered a column can be complex in the presence of subqueries. The
** result-set expression in all of the following SELECT statements is
** considered a column by this function.
**
** SELECT col FROM tbl;
** SELECT (SELECT col FROM tbl;
** SELECT (SELECT col FROM tbl);
** SELECT abc FROM (SELECT col AS abc FROM tbl);
**
** The declaration type for an expression is either TEXT, NUMERIC or ANY.
** The declaration type for a ROWID field is INTEGER.
** The declaration type for any expression other than a column is NULL.
*/
static const char *columnType(NameContext *pNC, Expr *pExpr){
char const *zType;
static const char *columnType(
NameContext *pNC,
Expr *pExpr,
const char **pzOriginDb,
const char **pzOriginTab,
const char **pzOriginCol
){
char const *zType = 0;
char const *zOriginDb = 0;
char const *zOriginTab = 0;
char const *zOriginCol = 0;
int j;
if( pExpr==0 || pNC->pSrcList==0 ) return 0;
@@ -781,17 +798,24 @@ static const char *columnType(NameContext *pNC, Expr *pExpr){
switch( pExpr->op ){
case TK_COLUMN: {
Table *pTab = 0;
int iCol = pExpr->iColumn;
/* The expression is a column. Locate the table the column is being
** extracted from in NameContext.pSrcList. This table may be real
** database table or a subquery.
*/
Table *pTab = 0; /* Table structure column is extracted from */
Select *pS = 0; /* Select the column is extracted from */
int iCol = pExpr->iColumn; /* Index of column in pTab */
while( pNC && !pTab ){
SrcList *pTabList = pNC->pSrcList;
for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
if( j<pTabList->nSrc ){
pTab = pTabList->a[j].pTab;
pS = pTabList->a[j].pSelect;
}else{
pNC = pNC->pNext;
}
}
if( pTab==0 ){
/* FIX ME:
** This can occurs if you have something like "SELECT new.x;" inside
@@ -806,30 +830,72 @@ static const char *columnType(NameContext *pNC, Expr *pExpr){
zType = "TEXT";
break;
}
assert( pTab );
if( iCol<0 ) iCol = pTab->iPKey;
assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
if( iCol<0 ){
zType = "INTEGER";
}else{
zType = pTab->aCol[iCol].zType;
#ifndef SQLITE_OMIT_SUBQUERY
if( pS ){
/* The "table" is actually a sub-select or a view in the FROM clause
** of the SELECT statement. Return the declaration type and origin
** data for the result-set column of the sub-select.
*/
if( iCol>=0 && iCol<pS->pEList->nExpr ){
/* If iCol is less than zero, then the expression requests the
** rowid of the sub-select or view. This expression is legal (see
** test case misc2.2.2) - it always evaluates to NULL.
*/
NameContext sNC;
Expr *p = pS->pEList->a[iCol].pExpr;
sNC.pSrcList = pS->pSrc;
sNC.pNext = 0;
sNC.pParse = pNC->pParse;
zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol);
}
}else
#endif
if( pTab->pSchema ){
/* A real table */
assert( !pS );
if( iCol<0 ) iCol = pTab->iPKey;
assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
if( iCol<0 ){
zType = "INTEGER";
zOriginCol = "rowid";
}else{
zType = pTab->aCol[iCol].zType;
zOriginCol = pTab->aCol[iCol].zName;
}
zOriginTab = pTab->zName;
if( pNC->pParse ){
int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
zOriginDb = pNC->pParse->db->aDb[iDb].zName;
}
}
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT: {
/* The expression is a sub-select. Return the declaration type and
** origin info for the single column in the result set of the SELECT
** statement.
*/
NameContext sNC;
Select *pS = pExpr->pSelect;
sNC.pSrcList = pExpr->pSelect->pSrc;
Expr *p = pS->pEList->a[0].pExpr;
sNC.pSrcList = pS->pSrc;
sNC.pNext = pNC;
zType = columnType(&sNC, pS->pEList->a[0].pExpr);
sNC.pParse = pNC->pParse;
zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol);
break;
}
#endif
default:
zType = 0;
}
if( pzOriginDb ){
assert( pzOriginTab && pzOriginCol );
*pzOriginDb = zOriginDb;
*pzOriginTab = zOriginTab;
*pzOriginCol = zOriginCol;
}
return zType;
}
@@ -846,14 +912,27 @@ static void generateColumnTypes(
int i;
NameContext sNC;
sNC.pSrcList = pTabList;
sNC.pParse = pParse;
for(i=0; i<pEList->nExpr; i++){
Expr *p = pEList->a[i].pExpr;
const char *zType = columnType(&sNC, p);
if( zType==0 ) continue;
const char *zOrigDb = 0;
const char *zOrigTab = 0;
const char *zOrigCol = 0;
const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
/* The vdbe must make it's own copy of the column-type, in case the
** schema is reset before this virtual machine is deleted.
**
** TODO: Create some symbol that is better than "-20" to pass to
** sqlite3VdbeSetColName(). As is this is a ticking bomb. An alternative
** is to pass the length of the string, but that means calling strlen()
** here which consumes code space. By passing a negative value that is
** not P3_DYNAMIC or P3_STATIC, strlen() is called by VdbeSetColName().
*/
sqlite3VdbeSetColName(v, i+pEList->nExpr, zType, strlen(zType));
sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, -20);
sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, -20);
sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, -20);
sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, -20);
}
}
@@ -891,7 +970,7 @@ static void generateColumnNames(
if( p==0 ) continue;
if( pEList->a[i].zName ){
char *zName = pEList->a[i].zName;
sqlite3VdbeSetColName(v, i, zName, strlen(zName));
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, strlen(zName));
continue;
}
if( p->op==TK_COLUMN && pTabList ){
@@ -909,7 +988,7 @@ static void generateColumnNames(
zCol = pTab->aCol[iCol].zName;
}
if( !shortNames && !fullNames && p->span.z && p->span.z[0] ){
sqlite3VdbeSetColName(v, i, (char*)p->span.z, p->span.n);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
}else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
char *zName = 0;
char *zTab;
@@ -917,18 +996,18 @@ static void generateColumnNames(
zTab = pTabList->a[j].zAlias;
if( fullNames || zTab==0 ) zTab = pTab->zName;
sqlite3SetString(&zName, zTab, ".", zCol, (char*)0);
sqlite3VdbeSetColName(v, i, zName, P3_DYNAMIC);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P3_DYNAMIC);
}else{
sqlite3VdbeSetColName(v, i, zCol, strlen(zCol));
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
}
}else if( p->span.z && p->span.z[0] ){
sqlite3VdbeSetColName(v, i, (char*)p->span.z, p->span.n);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
/* sqlite3VdbeCompressSpace(v, addr); */
}else{
char zName[30];
assert( p->op!=TK_COLUMN || pTabList==0 );
sprintf(zName, "column%d", i+1);
sqlite3VdbeSetColName(v, i, zName, 0);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, 0);
}
}
generateColumnTypes(pParse, pTabList, pEList);
@@ -1036,7 +1115,7 @@ Table *sqlite3ResultSetOfSelect(Parse *pParse, char *zTabName, Select *pSelect){
*/
memset(&sNC, 0, sizeof(sNC));
sNC.pSrcList = pSelect->pSrc;
zType = sqliteStrDup(columnType(&sNC, p));
zType = sqliteStrDup(columnType(&sNC, p, 0, 0, 0));
pCol->zType = zType;
pCol->affinity = sqlite3ExprAffinity(p);
pColl = sqlite3ExprCollSeq(pParse, p);
@@ -2783,13 +2862,6 @@ int sqlite3Select(
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto select_end;
/* Identify column names if we will be using them in a callback. This
** step is skipped if the output is going to some other destination.
*/
if( eDest==SRT_Callback ){
generateColumnNames(pParse, pTabList, pEList);
}
/* Generate code for all sub-queries in the FROM clause
*/
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
@@ -3217,6 +3289,14 @@ int sqlite3Select(
** successful coding of the SELECT.
*/
select_end:
/* Identify column names if we will be using them in a callback. This
** step is skipped if the output is going to some other destination.
*/
if( rc==SQLITE_OK && eDest==SRT_Callback ){
generateColumnNames(pParse, pTabList, pEList);
}
sqliteFree(sAggInfo.aCol);
sqliteFree(sAggInfo.aFunc);
return rc;