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]
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david.w.noon@ntlworld.com (David W Noon)
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