On Sun, 25 Oct 2009 20:17:22 -0400, Tom Lane wrote about Re: [GENERAL] Can the string literal syntax for function definitions please be dropped ?:
[snip] > <routine body> ::= > <SQL routine body> > | <external body reference> > > <SQL routine body> ::= <SQL procedure statement> > >and <SQL procedure statement> seems to allow one (count em, one) SQL >DDL or DML statement. So per spec, essentially every interesting case >requires an <external body reference>. This explains the evolution of DB2's support for user-defined functions: initially they (UDFs) had to be written in some host language (COBOL, PL/I, C, etc.), and linked in by external reference; later, a single SQL statement(*) was permitted instead; finally, a compound SQL statement was permitted, with BEGIN and END bracketing an arbitrary collection of other SQL statements. (*) Since all UDFs must return a value, the single statement was almost invariably a RETURN with some query providing the value. -- Regards, Dave [RLU #314465] ======================================================================= david.w.n...@ntlworld.com (David W Noon) ======================================================================= -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
