Docs patch to note that rules only get run once per query.

Поиск
Список
Период
Сортировка
От Sean Reifschneider
Тема Docs patch to note that rules only get run once per query.
Дата
Msg-id 20030413234349.GF7507@tummy.com
обсуждение исходный текст
Ответы Re: Docs patch to note that rules only get run once per query.  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-docs
I've made the following patch to the current CVS docs.  This is to
explain some confusion I ran into when trying to use rules.  After
reading the documentation on rules, I was expecting my rule to get run
at the end of a query where I deleted multiple rows, not after the first
row was deleted, then not any further.

I think the below text makes it more clear that this may happen and is
not a bug.

Sean

--- rules.sgml.old    2003-04-13 16:58:27.000000000 -0600
+++ rules.sgml    2003-04-13 17:26:53.000000000 -0600
@@ -32,6 +32,15 @@
      linkend="ONG90">.
 </para>

+<Note>
+ <Para>
+  Note that rules are only invoked once per query.  This may be a problem
+  in instances where the rule is updating a table based on another table's
+  contents, and you do a delete or update that changes multiple rows.  In
+  this case, you will have to use a trigger.
+ </Para>
+</Note>
+
 <Sect1 id="querytree">
 <Title>The Query Tree</Title>

--
 Do one thing every day that scares you.
                 -- Mary Schmich
Sean Reifschneider, Inimitably Superfluous <jafo@tummy.com>
tummy.com, ltd. - Linux Consulting since 1995.  Qmail, Python, SysAdmin


В списке pgsql-docs по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: 6.8.5: Location of CURRENT_DATE unclear
Следующее
От: Tom Lane
Дата:
Сообщение: Re: Docs patch to note that rules only get run once per query.