diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml index 3339a4b..65aeea3 100644 --- a/doc/src/sgml/ref/create_trigger.sgml +++ b/doc/src/sgml/ref/create_trigger.sgml @@ -26,7 +26,7 @@ PostgreSQL documentation -CREATE [ CONSTRAINT ] TRIGGER name { BEFORE | AFTER | INSTEAD OF } { event [ OR ... ] } +CREATE [ OR REPLACE ] [ CONSTRAINT ] TRIGGER name { BEFORE | AFTER | INSTEAD OF } { event [ OR ... ] } ON table_name [ FROM referenced_table_name ] [ NOT DEFERRABLE | [ DEFERRABLE ] [ INITIALLY IMMEDIATE | INITIALLY DEFERRED ] ] diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c index b7bcdd9..e742354 100644 --- a/src/backend/catalog/heap.c +++ b/src/backend/catalog/heap.c @@ -2371,7 +2371,8 @@ StoreRelCheck(Relation rel, const char *ccname, Node *expr, * Create the Check Constraint */ constrOid = - CreateConstraintEntry(ccname, /* Constraint Name */ + CreateConstraintEntry(InvalidOid, + ccname, /* Constraint Name */ RelationGetNamespace(rel), /* namespace */ CONSTRAINT_CHECK, /* Constraint Type */ false, /* Is Deferrable */ diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 67f637d..f247cbc 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1855,7 +1855,8 @@ index_constraint_create(Relation heapRelation, /* * Construct a pg_constraint entry. */ - conOid = CreateConstraintEntry(constraintName, + conOid = CreateConstraintEntry(InvalidOid, + constraintName, namespaceId, constraintType, deferrable, diff --git a/src/backend/catalog/pg_constraint.c b/src/backend/catalog/pg_constraint.c index 56568b0..06a2ead 100644 --- a/src/backend/catalog/pg_constraint.c +++ b/src/backend/catalog/pg_constraint.c @@ -45,10 +45,12 @@ * constraint) are *not* created here. But we do make dependency links * from the constraint to the things it depends on. * - * The new constraint's OID is returned. + * The new constraint's OID is returned. (This will be the same as + * "conOid" if that is specified as nonzero.) */ Oid -CreateConstraintEntry(const char *constraintName, +CreateConstraintEntry(Oid existing_constraint_oid, + const char *constraintName, Oid constraintNamespace, char constraintType, bool isDeferrable, @@ -79,7 +81,7 @@ CreateConstraintEntry(const char *constraintName, bool is_internal) { Relation conDesc; - Oid conOid; + Oid conOid = InvalidOid; HeapTuple tup; bool nulls[Natts_pg_constraint]; Datum values[Natts_pg_constraint]; @@ -92,7 +94,12 @@ CreateConstraintEntry(const char *constraintName, NameData cname; int i; ObjectAddress conobject; - + SysScanDesc conscan; + ScanKeyData skey[2]; + HeapTuple tuple; + bool replaces[Natts_pg_constraint]; + Form_pg_constraint constrForm; + conDesc = table_open(ConstraintRelationId, RowExclusiveLock); Assert(constraintName); @@ -164,9 +171,12 @@ CreateConstraintEntry(const char *constraintName, values[i] = (Datum) NULL; } - conOid = GetNewOidWithIndex(conDesc, ConstraintOidIndexId, - Anum_pg_constraint_oid); - values[Anum_pg_constraint_oid - 1] = ObjectIdGetDatum(conOid); + if (!existing_constraint_oid) + { + conOid = GetNewOidWithIndex(conDesc, ConstraintOidIndexId, + Anum_pg_constraint_oid); + values[Anum_pg_constraint_oid - 1] = ObjectIdGetDatum(conOid); + } values[Anum_pg_constraint_conname - 1] = NameGetDatum(&cname); values[Anum_pg_constraint_connamespace - 1] = ObjectIdGetDatum(constraintNamespace); values[Anum_pg_constraint_contype - 1] = CharGetDatum(constraintType); @@ -220,9 +230,47 @@ CreateConstraintEntry(const char *constraintName, else nulls[Anum_pg_constraint_conbin - 1] = true; - tup = heap_form_tuple(RelationGetDescr(conDesc), values, nulls); + if (OidIsValid(existing_constraint_oid)) + { + ScanKeyInit(&skey[0], + Anum_pg_constraint_oid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(existing_constraint_oid)); + + conscan = systable_beginscan(conDesc, + ConstraintOidIndexId, + true, + NULL, + 1, + skey); + + tuple = systable_getnext(conscan); + Assert (HeapTupleIsValid(tuple)); + constrForm = (Form_pg_constraint) GETSTRUCT(tuple); + conOid = constrForm->oid; + Assert(conOid == existing_constraint_oid); + + memset(replaces, true, sizeof(replaces)); + replaces[Anum_pg_constraint_oid - 1] = false; /* skip updating Oid data */ + replaces[Anum_pg_constraint_conname - 1] = false; + replaces[Anum_pg_constraint_confrelid - 1] = false; + + /* Modify the existing constraint entry */ + tup = heap_modify_tuple(tuple, RelationGetDescr(conDesc), values, nulls, replaces); + CatalogTupleUpdate(conDesc, &tuple->t_self, tup); + heap_freetuple(tup); - CatalogTupleInsert(conDesc, tup); + /* Remove all old dependencies before registering new ones */ + deleteDependencyRecordsFor(ConstraintRelationId, conOid, true); + + systable_endscan(conscan); + } + else + { + tup = heap_form_tuple(RelationGetDescr(conDesc), values, nulls); + CatalogTupleInsert(conDesc, tup); + heap_freetuple(tup); + } conobject.classId = ConstraintRelationId; conobject.objectId = conOid; diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 5440eb9..6890606 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8125,7 +8125,8 @@ addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint, Relation rel, /* * Record the FK constraint in pg_constraint. */ - constrOid = CreateConstraintEntry(conname, + constrOid = CreateConstraintEntry(InvalidOid, + conname, RelationGetNamespace(rel), CONSTRAINT_FOREIGN, fkconstraint->deferrable, @@ -8153,7 +8154,7 @@ addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint, Relation rel, conislocal, /* islocal */ coninhcount, /* inhcount */ connoinherit, /* conNoInherit */ - false); /* is_internal */ + false); /* is_internal */ ObjectAddressSet(address, ConstraintRelationId, constrOid); @@ -8393,7 +8394,8 @@ addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint, Relation rel, else conname = fkconstraint->conname; constrOid = - CreateConstraintEntry(conname, + CreateConstraintEntry(InvalidOid, + conname, RelationGetNamespace(partition), CONSTRAINT_FOREIGN, fkconstraint->deferrable, @@ -8788,7 +8790,8 @@ CloneFkReferencing(List **wqueue, Relation parentRel, Relation partRel) indexOid = constrForm->conindid; constrOid = - CreateConstraintEntry(fkconstraint->conname, + CreateConstraintEntry(InvalidOid, + fkconstraint->conname, constrForm->connamespace, CONSTRAINT_FOREIGN, fkconstraint->deferrable, diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 8d22d43..8ed3ff3 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -31,6 +31,7 @@ #include "catalog/pg_proc.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" +#include "catalog/pg_depend.h" #include "commands/dbcommands.h" #include "commands/defrem.h" #include "commands/trigger.h" @@ -180,7 +181,7 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, Relation pgrel; HeapTuple tuple; Oid funcrettype; - Oid trigoid; + Oid trigoid = InvalidOid; char internaltrigname[NAMEDATALEN]; char *trigname; Oid constrrelid = InvalidOid; @@ -189,6 +190,12 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, char *oldtablename = NULL; char *newtablename = NULL; bool partition_recurse; + bool is_update = false; + HeapTuple newtup; + TupleDesc tupDesc; + bool replaces[Natts_pg_trigger]; + Oid existing_constraint_oid = InvalidOid; + bool trigger_exists = false; if (OidIsValid(relOid)) rel = table_open(relOid, ShareRowExclusiveLock); @@ -685,6 +692,61 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, whenRtable = NIL; } + /* See if there is a pre-existing trigger of the same name */ + tgrel = table_open(TriggerRelationId, RowExclusiveLock); + + ScanKeyInit(&key, + Anum_pg_trigger_tgrelid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(RelationGetRelid(rel))); + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, + NULL, 1, &key); + while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) + { + Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); + + if (namestrcmp(&(pg_trigger->tgname), stmt->trigname) == 0) + { + trigoid = pg_trigger->oid; + existing_constraint_oid = pg_trigger->tgconstraint; + trigger_exists = true; + break; + } + } + systable_endscan(tgscan); + + /* Generate the trigger's oid because there was no same name trigger. */ + if (!trigger_exists) + trigoid = GetNewOidWithIndex(tgrel, TriggerOidIndexId, + Anum_pg_trigger_oid); + else + { + /* + * without OR REPLACE clause, can't override the trigger with the same name. + */ + if (!stmt->replace && !isInternal) + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("trigger \"%s\" for relation \"%s\" already exists", + stmt->trigname, RelationGetRelationName(rel)))); + /* + * CREATE OR REPLACE CONSTRAINT TRIGGER command can't replace non-constraint trigger. + */ + if (stmt->replace && stmt->isconstraint && !OidIsValid(existing_constraint_oid)) + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("Trigger \"%s\" for relation \"%s\" cannot be replaced with constraint trigger", + stmt->trigname, RelationGetRelationName(rel)))); + /* + * CREATE OR REPLACE TRIGGER command can't replace constraint trigger. + */ + if (stmt->replace && !stmt->isconstraint && OidIsValid(existing_constraint_oid)) + ereport(ERROR, + (errcode(ERRCODE_DUPLICATE_OBJECT), + errmsg("Constraint trigger \"%s\" for relation \"%s\" cannot be replaced with non-constraint trigger", + stmt->trigname, RelationGetRelationName(rel)))); + } + /* * Find and validate the trigger function. */ @@ -747,7 +809,8 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, { /* Internal callers should have made their own constraints */ Assert(!isInternal); - constraintOid = CreateConstraintEntry(stmt->trigname, + constraintOid = CreateConstraintEntry(existing_constraint_oid, + stmt->trigname, RelationGetNamespace(rel), CONSTRAINT_TRIGGER, stmt->deferrable, @@ -779,15 +842,6 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, } /* - * Generate the trigger's OID now, so that we can use it in the name if - * needed. - */ - tgrel = table_open(TriggerRelationId, RowExclusiveLock); - - trigoid = GetNewOidWithIndex(tgrel, TriggerOidIndexId, - Anum_pg_trigger_oid); - - /* * If trigger is internally generated, modify the provided trigger name to * ensure uniqueness by appending the trigger OID. (Callers will usually * supply a simple constant trigger name in these cases.) @@ -805,37 +859,6 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, } /* - * Scan pg_trigger for existing triggers on relation. We do this only to - * give a nice error message if there's already a trigger of the same - * name. (The unique index on tgrelid/tgname would complain anyway.) We - * can skip this for internally generated triggers, since the name - * modification above should be sufficient. - * - * NOTE that this is cool only because we have ShareRowExclusiveLock on - * the relation, so the trigger set won't be changing underneath us. - */ - if (!isInternal) - { - ScanKeyInit(&key, - Anum_pg_trigger_tgrelid, - BTEqualStrategyNumber, F_OIDEQ, - ObjectIdGetDatum(RelationGetRelid(rel))); - tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, - NULL, 1, &key); - while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) - { - Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); - - if (namestrcmp(&(pg_trigger->tgname), trigname) == 0) - ereport(ERROR, - (errcode(ERRCODE_DUPLICATE_OBJECT), - errmsg("trigger \"%s\" for relation \"%s\" already exists", - trigname, RelationGetRelationName(rel)))); - } - systable_endscan(tgscan); - } - - /* * Build the new pg_trigger tuple. * * When we're creating a trigger in a partition, we mark it as internal, @@ -962,12 +985,51 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, tuple = heap_form_tuple(tgrel->rd_att, values, nulls); - /* - * Insert tuple into pg_trigger. - */ - CatalogTupleInsert(tgrel, tuple); + if (!trigger_exists) + { + tuple = heap_form_tuple(tgrel->rd_att, values, nulls); + + /* + * Insert tuple into pg_trigger. + */ + CatalogTupleInsert(tgrel, tuple); + + heap_freetuple(tuple); + } + else + { + memset(replaces, true, sizeof(replaces)); + + ScanKeyInit(&key, + Anum_pg_trigger_tgrelid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(RelationGetRelid(rel))); + tgscan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, + NULL, 1, &key); + while (HeapTupleIsValid(tuple = systable_getnext(tgscan))) + { + Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple); + + if (namestrcmp(&(pg_trigger->tgname), trigname) == 0) + { + tupDesc = RelationGetDescr(tgrel); + replaces[Anum_pg_trigger_oid - 1] = false; /* skip updating Oid data */ + replaces[Anum_pg_trigger_tgrelid - 1] = false; + replaces[Anum_pg_trigger_tgname - 1] = false; + trigoid = pg_trigger->oid; + newtup = heap_modify_tuple(tuple, tupDesc, values, nulls, replaces); + + /* Update tuple in pg_trigger */ + CatalogTupleUpdate(tgrel, &tuple->t_self, newtup); + + heap_freetuple(newtup); + is_update = true; + break; + } + } + systable_endscan(tgscan); + } - heap_freetuple(tuple); table_close(tgrel, RowExclusiveLock); pfree(DatumGetPointer(values[Anum_pg_trigger_tgname - 1])); @@ -1010,6 +1072,15 @@ CreateTrigger(CreateTrigStmt *stmt, const char *queryString, myself.objectId = trigoid; myself.objectSubId = 0; + /* + * In case of replace trigger, trigger should no-more dependent on old + * referenced objects. Always remove the old dependencies and then + * register new ones. In that way, even if the old referenced object gets + * dropped, trigger will remain in the database. + */ + if (is_update) + deleteDependencyRecordsFor(myself.classId, myself.objectId, true); + referenced.classId = ProcedureRelationId; referenced.objectId = funcoid; referenced.objectSubId = 0; diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c index 89887b8..a6e3619 100644 --- a/src/backend/commands/typecmds.c +++ b/src/backend/commands/typecmds.c @@ -3146,7 +3146,8 @@ domainAddConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid, * Store the constraint in pg_constraint */ ccoid = - CreateConstraintEntry(constr->conname, /* Constraint Name */ + CreateConstraintEntry(InvalidOid, + constr->conname, /* Constraint Name */ domainNamespace, /* namespace */ CONSTRAINT_CHECK, /* Constraint Type */ false, /* Is Deferrable */ diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c508684..d0e8108 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -5353,48 +5353,50 @@ am_type: *****************************************************************************/ CreateTrigStmt: - CREATE TRIGGER name TriggerActionTime TriggerEvents ON + CREATE opt_or_replace TRIGGER name TriggerActionTime TriggerEvents ON qualified_name TriggerReferencing TriggerForSpec TriggerWhen EXECUTE FUNCTION_or_PROCEDURE func_name '(' TriggerFuncArgs ')' { CreateTrigStmt *n = makeNode(CreateTrigStmt); - n->trigname = $3; - n->relation = $7; - n->funcname = $13; - n->args = $15; - n->row = $9; - n->timing = $4; - n->events = intVal(linitial($5)); - n->columns = (List *) lsecond($5); - n->whenClause = $10; - n->transitionRels = $8; + n->replace = $2; + n->trigname = $4; + n->relation = $8; + n->funcname = $14; + n->args = $16; + n->row = $10; + n->timing = $5; + n->events = intVal(linitial($6)); + n->columns = (List *) lsecond($6); + n->whenClause = $11; + n->transitionRels = $9; n->isconstraint = false; n->deferrable = false; n->initdeferred = false; n->constrrel = NULL; $$ = (Node *)n; } - | CREATE CONSTRAINT TRIGGER name AFTER TriggerEvents ON + | CREATE opt_or_replace CONSTRAINT TRIGGER name AFTER TriggerEvents ON qualified_name OptConstrFromTable ConstraintAttributeSpec FOR EACH ROW TriggerWhen EXECUTE FUNCTION_or_PROCEDURE func_name '(' TriggerFuncArgs ')' { CreateTrigStmt *n = makeNode(CreateTrigStmt); - n->trigname = $4; - n->relation = $8; - n->funcname = $17; - n->args = $19; + n->replace = $2; + n->trigname = $5; + n->relation = $9; + n->funcname = $18; + n->args = $20; n->row = true; n->timing = TRIGGER_TYPE_AFTER; - n->events = intVal(linitial($6)); - n->columns = (List *) lsecond($6); - n->whenClause = $14; + n->events = intVal(linitial($7)); + n->columns = (List *) lsecond($7); + n->whenClause = $15; n->transitionRels = NIL; n->isconstraint = true; - processCASbits($10, @10, "TRIGGER", + processCASbits($11, @11, "TRIGGER", &n->deferrable, &n->initdeferred, NULL, NULL, yyscanner); - n->constrrel = $9; + n->constrrel = $10; $$ = (Node *)n; } ; diff --git a/src/include/catalog/pg_constraint.h b/src/include/catalog/pg_constraint.h index cbb5d9a..b6531e9 100644 --- a/src/include/catalog/pg_constraint.h +++ b/src/include/catalog/pg_constraint.h @@ -182,7 +182,8 @@ typedef enum ConstraintCategory } ConstraintCategory; -extern Oid CreateConstraintEntry(const char *constraintName, +extern Oid CreateConstraintEntry(Oid existing_constraint_oid, + const char *constraintName, Oid constraintNamespace, char constraintType, bool isDeferrable, diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index ff626cb..29349c7 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -2418,6 +2418,7 @@ typedef struct CreateTrigStmt bool isconstraint; /* This is a constraint trigger */ /* explicitly named transition data */ List *transitionRels; /* TriggerTransition nodes, or NIL if none */ + bool replace; /* T => replace if already exists */ /* The remaining fields are only used for constraint triggers */ bool deferrable; /* [NOT] DEFERRABLE */ bool initdeferred; /* INITIALLY {DEFERRED|IMMEDIATE} */ diff --git a/src/test/regress/expected/triggers.out b/src/test/regress/expected/triggers.out index 1e4053c..ff3a7b1 100644 --- a/src/test/regress/expected/triggers.out +++ b/src/test/regress/expected/triggers.out @@ -2918,3 +2918,27 @@ drop table self_ref; drop function dump_insert(); drop function dump_update(); drop function dump_delete(); +-- +-- Test case for CREATE OR REPLACE TRIGGER +-- +create table my_table (id integer); +create function before_replacement() returns trigger as $$ +begin +raise notice 'function replaced by another function'; +return null; +end; $$ language plpgsql; +create function after_replacement() returns trigger as $$ +begin +raise notice 'function to replace the initial function'; +return null; +end; $$ language plpgsql; +create or replace trigger my_trig before insert on my_table for each row execute procedure before_replacement(); +insert into my_table (id) values (1); +NOTICE: function replaced by another function +create or replace trigger my_trig before insert on my_table for each row execute procedure after_replacement(); +insert into my_table (id) values (2); +NOTICE: function to replace the initial function +drop trigger my_trig on my_table; +drop function before_replacement(); +drop function after_replacement(); +drop table my_table; diff --git a/src/test/regress/sql/triggers.sql b/src/test/regress/sql/triggers.sql index c21b6c1..6ab5cfb 100644 --- a/src/test/regress/sql/triggers.sql +++ b/src/test/regress/sql/triggers.sql @@ -2209,3 +2209,30 @@ drop table self_ref; drop function dump_insert(); drop function dump_update(); drop function dump_delete(); + +-- +-- Test case for CREATE OR REPLACE TRIGGER +-- +create table my_table (id integer); +create function before_replacement() returns trigger as $$ +begin +raise notice 'function replaced by another function'; +return null; +end; $$ language plpgsql; + +create function after_replacement() returns trigger as $$ +begin +raise notice 'function to replace the initial function'; +return null; +end; $$ language plpgsql; + +create or replace trigger my_trig before insert on my_table for each row execute procedure before_replacement(); +insert into my_table (id) values (1); + +create or replace trigger my_trig before insert on my_table for each row execute procedure after_replacement(); +insert into my_table (id) values (2); + +drop trigger my_trig on my_table; +drop function before_replacement(); +drop function after_replacement(); +drop table my_table;