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Overview
| Comment: | In UPDATE processing, include generated columns in the set of columns being updated if and only if their generator expressions reference some other column that is being updated. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | generated-columns |
| Files: | files | file ages | folders |
| SHA3-256: |
d38176e93a628e03f1bd8b689fbc4152 |
| User & Date: | drh 2019-10-22 13:59:23 |
Context
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2019-10-22
| ||
| 15:45 | Do not allow generated columns in the PRIMARY KEY. (check-in: 1a54743a user: drh tags: generated-columns) | |
| 13:59 | In UPDATE processing, include generated columns in the set of columns being updated if and only if their generator expressions reference some other column that is being updated. (check-in: d38176e9 user: drh tags: generated-columns) | |
| 13:01 | New testcase() macros. Fix a problem with INSERT when the IPK is to the right of generated columns. (check-in: 412799fc user: drh tags: generated-columns) | |
Changes
Changes to src/build.c.
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sqlite3 *db = pParse->db;
p = pParse->pNewTable;
if( p!=0 ){
pCol = &(p->aCol[p->nCol-1]);
if( !sqlite3ExprIsConstantOrFunction(pExpr, db->init.busy) ){
sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
pCol->zName);
}else{
/* A copy of pExpr is used instead of the original, as pExpr contains
** tokens that point to volatile memory.
*/
Expr x;
sqlite3ExprDelete(db, pCol->pDflt);
memset(&x, 0, sizeof(x));
................................................................................
assert( TF_HasStored==COLFLAG_STORED );
pTab->tabFlags |= eType;
pCol->pDflt = pExpr;
pExpr = 0;
goto generated_done;
generated_error:
sqlite3ErrorMsg(pParse, "incorrect GENERATED ALWAYS AS on column \"%s\"",
pCol->zName);
generated_done:
sqlite3ExprDelete(pParse->db, pExpr);
#else
/* Throw and error for the GENERATED ALWAYS AS clause if the
** SQLITE_OMIT_GENERATED_COLUMNS compile-time option is used. */
sqlite3ErrorMsg(pParse, "GENERATED ALWAYS AS not supported");
sqlite3ExprDelete(pParse->db, pExpr);
#endif
}
/*
** Generate code that will increment the schema cookie.
**
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sqlite3 *db = pParse->db;
p = pParse->pNewTable;
if( p!=0 ){
pCol = &(p->aCol[p->nCol-1]);
if( !sqlite3ExprIsConstantOrFunction(pExpr, db->init.busy) ){
sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
pCol->zName);
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
}else if( pCol->colFlags & COLFLAG_GENERATED ){
testcase( pCol->colflags & COLFLAG_VIRTUAL );
testcase( pCol->colflags & COLFLAG_STORED );
sqlite3ErrorMsg(pParse, "cannot use DEFAULT on a generated column");
#endif
}else{
/* A copy of pExpr is used instead of the original, as pExpr contains
** tokens that point to volatile memory.
*/
Expr x;
sqlite3ExprDelete(db, pCol->pDflt);
memset(&x, 0, sizeof(x));
................................................................................
assert( TF_HasStored==COLFLAG_STORED );
pTab->tabFlags |= eType;
pCol->pDflt = pExpr;
pExpr = 0;
goto generated_done;
generated_error:
sqlite3ErrorMsg(pParse, "error in generated column \"%s\"",
pCol->zName);
generated_done:
sqlite3ExprDelete(pParse->db, pExpr);
#else
/* Throw and error for the GENERATED ALWAYS AS clause if the
** SQLITE_OMIT_GENERATED_COLUMNS compile-time option is used. */
sqlite3ErrorMsg(pParse, "generated columns not supported");
sqlite3ExprDelete(pParse->db, pExpr);
#endif
}
/*
** Generate code that will increment the schema cookie.
**
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Changes to src/update.c.
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}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask. Unless this is a virtual table. In that
** case, set all bits of the colUsed mask (to ensure that the virtual
** table implementation makes all columns available).
*/
pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
................................................................................
/* Start scanning the virtual table */
pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
if( pWInfo==0 ) return;
/* Populate the argument registers. */
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
}else{
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* Enable sqlite3_vtab_nochange() */
}
}
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}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Mark generated columns as changing if their generator expressions
** reference any changing column. The actual aXRef[] value for
** generated expressions is not used, other than to check to see that it
** is non-negative, so the value of aXRef[] for generated columns can be
** set to any non-negative number. We use 99999 so that the value is
** obvious when looking at aXRef[] in a symbolic debugger.
*/
if( pTab->tabFlags & TF_HasGenerated ){
int bProgress;
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
do{
bProgress = 0;
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ) continue;
if( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 ) continue;
if( sqlite3ExprReferencesUpdatedColumn(pTab->aCol[i].pDflt,
aXRef, chngRowid) ){
aXRef[i] = 99999;
bProgress = 1;
}
}
}while( bProgress );
}
#endif
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask. Unless this is a virtual table. In that
** case, set all bits of the colUsed mask (to ensure that the virtual
** table implementation makes all columns available).
*/
pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
................................................................................
/* Start scanning the virtual table */
pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
if( pWInfo==0 ) return;
/* Populate the argument registers. */
for(i=0; i<pTab->nCol; i++){
assert( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 );
if( aXRef[i]>=0 ){
sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
}else{
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* Enable sqlite3_vtab_nochange() */
}
}
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