提交 3766e99c 编写于 作者: P Peter Eisentraut

Add a note that AND and OR are commutative. Apparently, they are not in

certain other products.
上级 4c3c8c04
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$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.163 2003/07/31 22:17:11 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.164 2003/08/04 14:00:13 petere Exp $
PostgreSQL documentation
-->
......@@ -162,6 +162,14 @@ PostgreSQL documentation
</tgroup>
</informaltable>
</para>
<para>
The operators <literal>AND</literal> and <literal>OR</literal> are
commutative, that is, you can switch the left and right operand
without affecting the result. But see <xref
linkend="syntax-express-eval"> for more information about the
order of evaluation of subexpressions.
</para>
</sect1>
<sect1 id="functions-comparison">
......
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$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.79 2003/06/19 23:22:40 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.80 2003/08/04 14:00:14 petere Exp $
-->
<chapter id="sql-syntax">
......@@ -1216,7 +1216,7 @@ SELECT name, (SELECT max(pop) FROM cities WHERE cities.state = states.name)
</para>
</sect2>
<sect2>
<sect2 id="syntax-express-eval">
<title>Expression Evaluation</title>
<para>
......
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