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Remove mention of factorial as casting example. New example needed.

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This commit is contained in:
Bruce Momjian 2003-12-01 21:53:15 +00:00
parent 04a4821ade
commit e2ac58c7bd
1 changed files with 1 additions and 25 deletions
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26
doc/src/sgml/typeconv.sgml
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@ -1,5 +1,5 @@
<!-- <!--
$PostgreSQL: pgsql/doc/src/sgml/typeconv.sgml,v 1.39 2003/11/29 19:51:38 pgsql Exp $ $PostgreSQL: pgsql/doc/src/sgml/typeconv.sgml,v 1.40 2003/12/01 21:53:15 momjian Exp $
--> -->
<chapter Id="typeconv"> <chapter Id="typeconv">
@ -437,30 +437,6 @@ SELECT @ '-4.5e500' AS "abs";
ERROR: "-4.5e500" is out of range for type double precision ERROR: "-4.5e500" is out of range for type double precision
</screen> </screen>
</para> </para>
<para>
On the other hand, the postfix operator <literal>!</> (factorial)
is defined only for integer data types, not for <type>float8</type>. So, if we
try a similar case with <literal>!</>, we get:
<screen>
SELECT '20' ! AS "factorial";
ERROR: operator is not unique: "unknown" !
HINT: Could not choose a best candidate operator. You may need to add explicit
type casts.
</screen>
This happens because the system can't decide which of the several
possible <literal>!</> operators should be preferred. We can help
it out with an explicit cast:
<screen>
SELECT CAST('20' AS int8) ! AS "factorial";
factorial
---------------------
2432902008176640000
(1 row)
</screen>
</para>
</example> </example>
</sect1> </sect1>