diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-02-16 02:30:39 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-02-16 02:30:39 +0000 |
| commit | 51972a9d5d068dd34b24ff4923981ffb90e5cc2d (patch) | |
| tree | c68fddbb3eaafbd332e84afbafe3c171f6372d4e /doc/src | |
| parent | de25638d2fbe9e56ecfc60a7dda8a0c56028317a (diff) | |
COALESCE() and NULLIF() are now first-class expressions, not macros
that turn into CASE expressions. They evaluate their arguments at most
once. Patch by Kris Jurka, review and (very light) editorializing by me.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 13 |
1 files changed, 1 insertions, 12 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f2d84a969aa..fd247be28c2 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.139 2003/02/13 05:24:01 momjian Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.140 2003/02/16 02:30:36 tgl Exp $ PostgreSQL documentation --> @@ -6295,17 +6295,6 @@ SELECT NULLIF(value, '(none)') ... </programlisting> </para> - <tip> - <para> - <function>COALESCE</function> and <function>NULLIF</function> are - just shorthand for <token>CASE</token> expressions. They are actually - converted into <token>CASE</token> expressions at a very early stage - of processing, and subsequent processing thinks it is dealing with - <token>CASE</token>. Thus an incorrect <function>COALESCE</function> or - <function>NULLIF</function> usage may draw an error message that - refers to <token>CASE</token>. - </para> - </tip> </sect2> </sect1> |