Function IsThereCollationInNamespace

src/backend/commands/collationcmds.c:298–321

* Subroutine for ALTER COLLATION SET SCHEMA and RENAME * * Is there a collation with the same name of the given collation already in * the given namespace? If so, raise an appropriate error message. */

 * the given namespace?  If so, raise an appropriate error message.
 */
void
IsThereCollationInNamespace(const char *collname, Oid nspOid)
{
	/* make sure the name doesn't already exist in new schema */
	if (SearchSysCacheExists3(COLLNAMEENCNSP,
							  CStringGetDatum(collname),
							  Int32GetDatum(GetDatabaseEncoding()),
							  ObjectIdGetDatum(nspOid)))
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("collation \"%s\" for encoding \"%s\" already exists in schema \"%s\"",
						collname, GetDatabaseEncodingName(),
						get_namespace_name(nspOid))));

	/* mustn't match an any-encoding entry, either */
	if (SearchSysCacheExists3(COLLNAMEENCNSP,
							  CStringGetDatum(collname),
							  Int32GetDatum(-1),
							  ObjectIdGetDatum(nspOid)))
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("collation \"%s\" already exists in schema \"%s\"",
						collname, get_namespace_name(nspOid))));
}

/*
 * ALTER COLLATION