Index: src/fkey.c ================================================================== --- src/fkey.c +++ src/fkey.c @@ -620,12 +620,12 @@ Table *pTab, /* Table being updated or deleted from */ FKey *pFKey, /* Foreign key to get action for */ ExprList *pChanges /* Change-list for UPDATE, NULL for DELETE */ ){ sqlite3 *db = pParse->db; /* Database handle */ - int action; - Trigger *pTrigger; + int action; /* One of OE_None, OE_Cascade etc. */ + Trigger *pTrigger; /* Trigger definition to return */ if( pChanges ){ action = pFKey->updateConf; pTrigger = pFKey->pOnUpdate; }else{ @@ -635,47 +635,30 @@ assert( OE_SetNull>OE_Restrict && OE_SetDflt>OE_Restrict ); assert( OE_Cascade>OE_Restrict && OE_NoneOE_Restrict && !pTrigger ){ + u8 enableLookaside; /* Copy of db->lookaside.bEnabled */ char const *zFrom; /* Name of referencing table */ int nFrom; /* Length in bytes of zFrom */ - Index *pIdx = 0; - int *aiCol = 0; - TriggerStep *pStep; - sqlite3 *dbMem = pTab->dbMem; - Expr *pWhere = 0; - ExprList *pList = 0; - int i; + Index *pIdx = 0; /* Parent key index for this FK */ + int *aiCol = 0; /* child table cols -> parent key cols */ + TriggerStep *pStep; /* First (only) step of trigger program */ + Expr *pWhere = 0; /* WHERE clause of trigger step */ + ExprList *pList = 0; /* Changes list if ON UPDATE CASCADE */ + int i; /* Iterator variable */ if( locateFkeyIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0; assert( aiCol || pFKey->nCol==1 ); - assert( dbMem==0 || dbMem==pParse->db ); - zFrom = pFKey->pFrom->zName; - nFrom = sqlite3Strlen30(zFrom); - pTrigger = (Trigger *)sqlite3DbMallocZero(dbMem, - sizeof(Trigger) + /* struct Trigger */ - sizeof(TriggerStep) + /* Single step in trigger program */ - nFrom + 1 /* Space for pStep->target.z */ - ); - if( !pTrigger ){ - pParse->db->mallocFailed = 1; - return 0; - } - pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1]; - pStep->target.z = (char *)&pStep[1]; - pStep->target.n = nFrom; - memcpy((char *)pStep->target.z, zFrom, nFrom); - for(i=0; inCol; i++){ - Expr *pEq; - int iFromCol; /* Idx of column in referencing table */ + Token tOld = { "old", 3 }; /* Literal "old" token */ + Token tNew = { "new", 3 }; /* Literal "new" token */ Token tFromCol; /* Name of column in referencing table */ Token tToCol; /* Name of column in referenced table */ - Token tOld = { "old", 3 }; /* Literal "old" token */ - Token tNew = { "new", 3 }; /* Literal "new" token */ + int iFromCol; /* Idx of column in referencing table */ + Expr *pEq; /* tFromCol = OLD.tToCol */ iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom; tToCol.z = pIdx ? pTab->aCol[pIdx->aiColumn[i]].zName : "oid"; tFromCol.z = iFromCol<0 ? "oid" : pFKey->pFrom->aCol[iFromCol].zName; @@ -688,11 +671,11 @@ sqlite3PExpr(pParse, TK_DOT, sqlite3PExpr(pParse, TK_ID, 0, 0, &tOld), sqlite3PExpr(pParse, TK_ID, 0, 0, &tToCol) , 0) , 0); - pWhere = sqlite3ExprAnd(pParse->db, pWhere, pEq); + pWhere = sqlite3ExprAnd(db, pWhere, pEq); if( action!=OE_Cascade || pChanges ){ Expr *pNew; if( action==OE_Cascade ){ pNew = sqlite3PExpr(pParse, TK_DOT, @@ -711,16 +694,46 @@ } pList = sqlite3ExprListAppend(pParse, pList, pNew); sqlite3ExprListSetName(pParse, pList, &tFromCol, 0); } } - sqlite3DbFree(pParse->db, aiCol); + sqlite3DbFree(db, aiCol); + + /* If pTab->dbMem==0, then the table may be part of a shared-schema. + ** Disable the lookaside buffer before allocating space for the + ** trigger definition in this case. */ + enableLookaside = db->lookaside.bEnabled; + if( pTab->dbMem==0 ){ + db->lookaside.bEnabled = 0; + } + + zFrom = pFKey->pFrom->zName; + nFrom = sqlite3Strlen30(zFrom); + pTrigger = (Trigger *)sqlite3DbMallocZero(db, + sizeof(Trigger) + /* struct Trigger */ + sizeof(TriggerStep) + /* Single step in trigger program */ + nFrom + 1 /* Space for pStep->target.z */ + ); + if( pTrigger ){ + pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1]; + pStep->target.z = (char *)&pStep[1]; + pStep->target.n = nFrom; + memcpy((char *)pStep->target.z, zFrom, nFrom); + + pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE); + pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE); + } - pStep->pWhere = sqlite3ExprDup(dbMem, pWhere, EXPRDUP_REDUCE); - pStep->pExprList = sqlite3ExprListDup(dbMem, pList, EXPRDUP_REDUCE); + /* Re-enable the lookaside buffer, if it was disabled earlier. */ + db->lookaside.bEnabled = enableLookaside; + sqlite3ExprDelete(pParse->db, pWhere); sqlite3ExprListDelete(pParse->db, pList); + if( db->mallocFailed==1 ){ + fkTriggerDelete(db, pTrigger); + return 0; + } pStep->op = (action!=OE_Cascade || pChanges) ? TK_UPDATE : TK_DELETE; pStep->pTrig = pTrigger; pTrigger->pSchema = pTab->pSchema; pTrigger->pTabSchema = pTab->pSchema; Index: test/fkey2.test ================================================================== --- test/fkey2.test +++ test/fkey2.test @@ -41,10 +41,13 @@ # # fkey2-6.*: Test that FK processing is automatically disabled when # running VACUUM. # # fkey2-7.*: Test using an IPK as the key in the child (referencing) table. +# +# fkey2-8.*: Test that enabling/disabling foreign key support while a +# transaction is active is not possible. # # fkey2-genfkey.*: Tests that were used with the shell tool .genfkey # command. Recycled to test the built-in implementation. # @@ -412,10 +415,11 @@ } #------------------------------------------------------------------------- # Test that it is possible to use an INTEGER PRIMARY KEY as the child key # of a foreign constraint. +# drop_all_tables do_test fkey2-7.1 { execsql { CREATE TABLE t1(a PRIMARY KEY, b); CREATE TABLE t2(c INTEGER PRIMARY KEY REFERENCES t1, b); @@ -444,10 +448,36 @@ execsql { DELETE FROM t1 WHERE a = 1 } } {} do_test fkey2-7.8 { catchsql { UPDATE t1 SET a = 3 } } {1 {foreign key constraint failed}} + +#------------------------------------------------------------------------- +# Test that it is not possible to enable/disable FK support while a +# transaction is open. +# +drop_all_tables +proc fkey2-8-test {tn zSql value} { + do_test fkey-2.8.$tn.1 [list execsql $zSql] {} + do_test fkey-2.8.$tn.2 { execsql "PRAGMA foreign_keys" } $value +} +fkey2-8-test 1 { PRAGMA foreign_keys = 0 } 0 +fkey2-8-test 2 { PRAGMA foreign_keys = 1 } 1 +fkey2-8-test 3 { BEGIN } 1 +fkey2-8-test 4 { PRAGMA foreign_keys = 0 } 1 +fkey2-8-test 5 { COMMIT } 1 +fkey2-8-test 6 { PRAGMA foreign_keys = 0 } 0 +fkey2-8-test 7 { BEGIN } 0 +fkey2-8-test 8 { PRAGMA foreign_keys = 1 } 0 +fkey2-8-test 9 { COMMIT } 0 +fkey2-8-test 10 { PRAGMA foreign_keys = 1 } 1 +fkey2-8-test 11 { PRAGMA foreign_keys = off } 0 +fkey2-8-test 12 { PRAGMA foreign_keys = on } 1 +fkey2-8-test 13 { PRAGMA foreign_keys = no } 0 +fkey2-8-test 14 { PRAGMA foreign_keys = yes } 1 +fkey2-8-test 15 { PRAGMA foreign_keys = false } 0 +fkey2-8-test 16 { PRAGMA foreign_keys = true } 1 #------------------------------------------------------------------------- # The following block of tests, those prefixed with "fkey2-genfkey.", are # the same tests that were used to test the ".genfkey" command provided # by the shell tool. So these tests show that the built-in foreign key ADDED test/fkey_malloc.test Index: test/fkey_malloc.test ================================================================== --- test/fkey_malloc.test +++ test/fkey_malloc.test @@ -0,0 +1,36 @@ +# 2009 September 22 +# +# 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. +# +#*********************************************************************** +# +# + +set testdir [file dirname $argv0] +source $testdir/tester.tcl + +ifcapable !foreignkey||!trigger { + finish_test + return +} +source $testdir/malloc_common.tcl + +do_malloc_test fkey_malloc-1 -sqlprep { + PRAGMA foreign_keys = 1; + CREATE TABLE t1(a PRIMARY KEY, b); + CREATE TABLE t2(x REFERENCES t1 ON UPDATE CASCADE ON DELETE CASCADE); +} -sqlbody { + INSERT INTO t1 VALUES('aaa', 1); + INSERT INTO t2 VALUES('aaa'); + UPDATE t1 SET a = 'bbb'; + DELETE FROM t1; +} + +finish_test + +