database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00
Code Activity

Update SQL-command reference pages for schema features.

Browse Source
This commit is contained in:
Tom Lane
2002-04-23 02:07:16 +00:00
parent 5dd1c713d0
commit 0c1fe3d2b9
38 changed files with 366 additions and 205 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
doc/src/sgml/ref/create_function.sgml
View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.36 2002/04/11 19:59:55 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.37 2002/04/23 02:07:15 tgl Exp $
-->
<refentry id="SQL-CREATEFUNCTION">
@ -44,9 +44,14 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<listitem>
<para>
The name of a function to create. The name need not be unique,
because functions may be overloaded, but functions with the
same name must have different argument types.
The name of a function to create. If a schema name is included,
then the function is created in the
specified schema. Otherwise it is created in the current schema (the
one at the front of the search path; see <literal>CURRENT_SCHEMA()</>).
The name of the new function must not match any existing function
with the same argument types in the same schema. However, functions of
different argument types may share a name (this is called
<firstterm>overloading</>).
</para>
</listitem>
</varlistentry>
@ -332,8 +337,9 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
</title>
<para>
A function that has one parameter and is named the same as its output
datatype is considered to be a <firstterm>type coercion function</>:
it can be invoked to convert a value of its input datatype into a value
datatype (including the schema name) is considered to be a <firstterm>type
coercion function</>: it can be invoked to convert a value of its input
datatype into a value
of its output datatype. For example,
<programlisting>
SELECT CAST(42 AS text);