database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-11 01:42:22 +03:00
Code Activity

Omit unnecessary CHECK constraints in UPDATE statements, when none of the

Browse Source 
columns referenced in the CHECK constraint are modified.

FossilOrigin-Name: 02fbdbc782dd98f080bf4482d820f36c0ef3d519
This commit is contained in:
drh
2016-02-10 16:52:24 +00:00
parent bdb00225ab
commit 2a0b527b37
4 changed files with 44 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
src/insert.c
View File

@@ -1077,6 +1077,38 @@ insert_cleanup:
#undef tmask
#endif
/* This is the Walker callback from checkConstraintUnchanged(). Set
** pWalker->eCode to 0 if this expression node references any of the
** columns that are being modifed by an UPDATE statement.
*/
static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN
&& pExpr->iColumn>=0
&& pWalker->u.aiCol[pExpr->iColumn]>=0
){
pWalker->eCode = 0;
}
return WRC_Continue;
}
/*
** pExpr is a CHECK constraint on a row that is being UPDATE-ed. The
** only columns that are modified by the UPDATE are those for which
** aiChng[i]>=0. Return true if CHECK constraint pExpr does not use
** any of the changing columns. In other words, return true if this
** CHECK constraint can be skipped when validating the new row in
** the UPDATE statement.
*/
static int checkConstraintUnchanged(Expr *pExpr, int *aiChng){
Walker w;
memset(&w, 0, sizeof(w));
w.eCode = 1;
w.xExprCallback = checkConstraintExprNode;
w.u.aiCol = aiChng;
sqlite3WalkExpr(&w, pExpr);
return w.eCode;
}
/*
** Generate code to do constraint checks prior to an INSERT or an UPDATE
** on table pTab.
@@ -1275,7 +1307,9 @@ void sqlite3GenerateConstraintChecks(
onError = overrideError!=OE_Default ? overrideError : OE_Abort;
for(i=0; i<pCheck->nExpr; i++){
int allOk = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfTrue(pParse, pCheck->a[i].pExpr, allOk, SQLITE_JUMPIFNULL);
Expr *pExpr = pCheck->a[i].pExpr;
if( aiChng && checkConstraintUnchanged(pExpr, aiChng) ) continue;
sqlite3ExprIfTrue(pParse, pExpr, allOk, SQLITE_JUMPIFNULL);
if( onError==OE_Ignore ){
sqlite3VdbeGoto(v, ignoreDest);
}else{