Long time ago, I propose regclass like function which does not throw an error if the table is not found. Instead I want to let it return InvalidOid or NULL.
>> Tatsuo Ishii <is...@postgresql.org> writes: >> > Is there any way to use regclass without having ERROR? >> >> > pgpool-II needs to find the oid from table name and for the purpose it >> > issues something like "SELECT 'table_name'::regproc::oid". Problem is, >> > if the table does not exist, an error occured and the transaction >> > aborts. Ideally if the table does not exist, the SELECT returns 0 >> > (InvalidOid). >> >> I don't think the cast should act that way, but I could see providing a >> separate conversion function that returns 0 ... or perhaps better NULL >> ... if no match. > > Such a function should be very helpfull. Great! I made pretty simple function for this. Essential part is something like this: Datum pgpool_regclass(PG_FUNCTION_ARGS) { char *pro_name_or_oid = PG_GETARG_CSTRING(0); Oid result; PG_TRY(); { result = DirectFunctionCall1(regclassin, CStringGetDatum(pro_name_or_oid)); } PG_CATCH(); { result = InvalidOid; } PG_END_TRY(); PG_RETURN_OID(result); } IMO this implementation is the least invasive but not so elegant. Before proposing more complete patches, I would like to hear comments: which way I should go? The least invasive one like above? Or Should I refactor regclassin, for example implementing "regclassin_gut" which do the essential job, and making wrapper functions, one is active existing regclass, and the other act as new one? -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese: http://www.sraoss.co.jp -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers