Ooops, fix busted markup.

This commit is contained in:
Tom Lane 2002-06-15 22:15:03 +00:00
parent 32fecad80a
commit 62d4526114
1 changed files with 3 additions and 3 deletions

View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.62 2002/06/15 21:28:55 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/syntax.sgml,v 1.63 2002/06/15 22:15:03 tgl Exp $
-->
<chapter id="sql-syntax">
@ -1471,11 +1471,11 @@ SELECT somefunc() OR true;
be used. For example, this is an untrustworthy way of trying to
avoid division by zero in a WHERE clause:
<programlisting>
SELECT ... WHERE x <> 0 AND y/x > 1.5;
SELECT ... WHERE x &lt;&gt; 0 AND y/x &gt; 1.5;
</programlisting>
but this is safe:
<programlisting>
SELECT ... WHERE CASE WHEN x <> 0 THEN y/x > 1.5 ELSE false END;
SELECT ... WHERE CASE WHEN x &lt;&gt; 0 THEN y/x &gt; 1.5 ELSE false END;
</programlisting>
A CASE construct used in this fashion will defeat optimization attempts,
so it should only be done when necessary.