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-rw-r--r--src/backend/catalog/pg_enum.c85
-rw-r--r--src/backend/commands/typecmds.c20
-rw-r--r--src/backend/nodes/copyfuncs.c3
-rw-r--r--src/backend/nodes/equalfuncs.c3
-rw-r--r--src/backend/parser/gram.y20
5 files changed, 120 insertions, 11 deletions
diff --git a/src/backend/catalog/pg_enum.c b/src/backend/catalog/pg_enum.c
index c66f9632c29..1f0ffcfa159 100644
--- a/src/backend/catalog/pg_enum.c
+++ b/src/backend/catalog/pg_enum.c
@@ -466,6 +466,91 @@ restart:
/*
+ * RenameEnumLabel
+ * Rename a label in an enum set.
+ */
+void
+RenameEnumLabel(Oid enumTypeOid,
+ const char *oldVal,
+ const char *newVal)
+{
+ Relation pg_enum;
+ HeapTuple enum_tup;
+ Form_pg_enum en;
+ CatCList *list;
+ int nelems;
+ HeapTuple old_tup;
+ bool found_new;
+ int i;
+
+ /* check length of new label is ok */
+ if (strlen(newVal) > (NAMEDATALEN - 1))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_NAME),
+ errmsg("invalid enum label \"%s\"", newVal),
+ errdetail("Labels must be %d characters or less.",
+ NAMEDATALEN - 1)));
+
+ /*
+ * Acquire a lock on the enum type, which we won't release until commit.
+ * This ensures that two backends aren't concurrently modifying the same
+ * enum type. Since we are not changing the type's sort order, this is
+ * probably not really necessary, but there seems no reason not to take
+ * the lock to be sure.
+ */
+ LockDatabaseObject(TypeRelationId, enumTypeOid, 0, ExclusiveLock);
+
+ pg_enum = heap_open(EnumRelationId, RowExclusiveLock);
+
+ /* Get the list of existing members of the enum */
+ list = SearchSysCacheList1(ENUMTYPOIDNAME,
+ ObjectIdGetDatum(enumTypeOid));
+ nelems = list->n_members;
+
+ /*
+ * Locate the element to rename and check if the new label is already in
+ * use. (The unique index on pg_enum would catch that anyway, but we
+ * prefer a friendlier error message.)
+ */
+ old_tup = NULL;
+ found_new = false;
+ for (i = 0; i < nelems; i++)
+ {
+ enum_tup = &(list->members[i]->tuple);
+ en = (Form_pg_enum) GETSTRUCT(enum_tup);
+ if (strcmp(NameStr(en->enumlabel), oldVal) == 0)
+ old_tup = enum_tup;
+ if (strcmp(NameStr(en->enumlabel), newVal) == 0)
+ found_new = true;
+ }
+ if (!old_tup)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("\"%s\" is not an existing enum label",
+ oldVal)));
+ if (found_new)
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("enum label \"%s\" already exists",
+ newVal)));
+
+ /* OK, make a writable copy of old tuple */
+ enum_tup = heap_copytuple(old_tup);
+ en = (Form_pg_enum) GETSTRUCT(enum_tup);
+
+ ReleaseCatCacheList(list);
+
+ /* Update the pg_enum entry */
+ namestrcpy(&en->enumlabel, newVal);
+ simple_heap_update(pg_enum, &enum_tup->t_self, enum_tup);
+ CatalogUpdateIndexes(pg_enum, enum_tup);
+ heap_freetuple(enum_tup);
+
+ heap_close(pg_enum, RowExclusiveLock);
+}
+
+
+/*
* RenumberEnumType
* Renumber existing enum elements to have sort positions 1..n.
*
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 6cc7106467d..41fd2dae7f8 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1241,17 +1241,25 @@ AlterEnum(AlterEnumStmt *stmt)
/* Check it's an enum and check user has permission to ALTER the enum */
checkEnumOwner(tup);
- /* Add the new label */
- AddEnumLabel(enum_type_oid, stmt->newVal,
- stmt->newValNeighbor, stmt->newValIsAfter,
- stmt->skipIfExists);
+ ReleaseSysCache(tup);
+
+ if (stmt->oldVal)
+ {
+ /* Rename an existing label */
+ RenameEnumLabel(enum_type_oid, stmt->oldVal, stmt->newVal);
+ }
+ else
+ {
+ /* Add a new label */
+ AddEnumLabel(enum_type_oid, stmt->newVal,
+ stmt->newValNeighbor, stmt->newValIsAfter,
+ stmt->skipIfNewValExists);
+ }
InvokeObjectPostAlterHook(TypeRelationId, enum_type_oid, 0);
ObjectAddressSet(address, TypeRelationId, enum_type_oid);
- ReleaseSysCache(tup);
-
return address;
}
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index be2207e3188..4f39dad66b4 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3375,10 +3375,11 @@ _copyAlterEnumStmt(const AlterEnumStmt *from)
AlterEnumStmt *newnode = makeNode(AlterEnumStmt);
COPY_NODE_FIELD(typeName);
+ COPY_STRING_FIELD(oldVal);
COPY_STRING_FIELD(newVal);
COPY_STRING_FIELD(newValNeighbor);
COPY_SCALAR_FIELD(newValIsAfter);
- COPY_SCALAR_FIELD(skipIfExists);
+ COPY_SCALAR_FIELD(skipIfNewValExists);
return newnode;
}
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index c4ec4077a60..4800165a919 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1465,10 +1465,11 @@ static bool
_equalAlterEnumStmt(const AlterEnumStmt *a, const AlterEnumStmt *b)
{
COMPARE_NODE_FIELD(typeName);
+ COMPARE_STRING_FIELD(oldVal);
COMPARE_STRING_FIELD(newVal);
COMPARE_STRING_FIELD(newValNeighbor);
COMPARE_SCALAR_FIELD(newValIsAfter);
- COMPARE_SCALAR_FIELD(skipIfExists);
+ COMPARE_SCALAR_FIELD(skipIfNewValExists);
return true;
}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index b69a77a588f..1526c73a1c5 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -5257,30 +5257,44 @@ AlterEnumStmt:
{
AlterEnumStmt *n = makeNode(AlterEnumStmt);
n->typeName = $3;
+ n->oldVal = NULL;
n->newVal = $7;
n->newValNeighbor = NULL;
n->newValIsAfter = true;
- n->skipIfExists = $6;
+ n->skipIfNewValExists = $6;
$$ = (Node *) n;
}
| ALTER TYPE_P any_name ADD_P VALUE_P opt_if_not_exists Sconst BEFORE Sconst
{
AlterEnumStmt *n = makeNode(AlterEnumStmt);
n->typeName = $3;
+ n->oldVal = NULL;
n->newVal = $7;
n->newValNeighbor = $9;
n->newValIsAfter = false;
- n->skipIfExists = $6;
+ n->skipIfNewValExists = $6;
$$ = (Node *) n;
}
| ALTER TYPE_P any_name ADD_P VALUE_P opt_if_not_exists Sconst AFTER Sconst
{
AlterEnumStmt *n = makeNode(AlterEnumStmt);
n->typeName = $3;
+ n->oldVal = NULL;
n->newVal = $7;
n->newValNeighbor = $9;
n->newValIsAfter = true;
- n->skipIfExists = $6;
+ n->skipIfNewValExists = $6;
+ $$ = (Node *) n;
+ }
+ | ALTER TYPE_P any_name RENAME VALUE_P Sconst TO Sconst
+ {
+ AlterEnumStmt *n = makeNode(AlterEnumStmt);
+ n->typeName = $3;
+ n->oldVal = $6;
+ n->newVal = $8;
+ n->newValNeighbor = NULL;
+ n->newValIsAfter = false;
+ n->skipIfNewValExists = false;
$$ = (Node *) n;
}
;
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-07 16:35:42 +0000