diff options
Diffstat (limited to 'doc/src/sgml/ref/create_function.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_function.sgml | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml index b95c2fd24e6..2a28925dff5 100644 --- a/doc/src/sgml/ref/create_function.sgml +++ b/doc/src/sgml/ref/create_function.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.23 2001/05/19 09:01:10 petere Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.24 2001/06/04 23:27:23 momjian Exp $ --> <refentry id="SQL-CREATEFUNCTION"> @@ -55,10 +55,16 @@ CREATE FUNCTION <replaceable class="parameter">name</replaceable> ( [ <replaceab <listitem> <para> The data type(s) of the function's arguments, if any. The - input types may be base or complex types, or - <literal>opaque</literal>. <literal>Opaque</literal> indicates + input types may be base or complex types, + <literal>opaque</literal>, or the same as the type of an + existing column. <literal>Opaque</literal> indicates that the function accepts arguments of a non-SQL type such as <type>char *</type>. + The type of a column is indicated using <replaceable + class="parameter">tablename</replaceable>.<replaceable + class="parameter">columnname</replaceable><literal>%TYPE</literal>; + using this can sometimes help make a function independent from + changes to the definition of a table. </para> </listitem> </varlistentry> @@ -69,8 +75,10 @@ CREATE FUNCTION <replaceable class="parameter">name</replaceable> ( [ <replaceab <listitem> <para> The return data type. The output type may be specified as a - base type, complex type, <literal>setof</literal> type, or - <literal>opaque</literal>. The <literal>setof</literal> + base type, complex type, <literal>setof</literal> type, + <literal>opaque</literal>, or the same as the type of an + existing column. + The <literal>setof</literal> modifier indicates that the function will return a set of items, rather than a single item. Functions with a declared return type of <literal>opaque</literal> do not return a value. |