1998-09-07 17:58:31 +02:00
|
|
|
<REFENTRY ID="SQL-CREATEFUNCTION">
|
1998-05-13 07:34:00 +02:00
|
|
|
<REFMETA>
|
|
|
|
<REFENTRYTITLE>
|
|
|
|
CREATE FUNCTION
|
|
|
|
</REFENTRYTITLE>
|
|
|
|
<REFMISCINFO>SQL - Language Statements</REFMISCINFO>
|
|
|
|
</REFMETA>
|
|
|
|
<REFNAMEDIV>
|
|
|
|
<REFNAME>
|
|
|
|
CREATE FUNCTION
|
|
|
|
</REFNAME>
|
|
|
|
<REFPURPOSE>
|
|
|
|
Defines a new function
|
|
|
|
</REFPURPOSE>
|
|
|
|
|
|
|
|
<REFSYNOPSISDIV>
|
|
|
|
<REFSYNOPSISDIVINFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSYNOPSISDIVINFO>
|
|
|
|
<SYNOPSIS>
|
|
|
|
CREATE FUNCTION <replaceable class="parameter">name</replaceable> ([<replaceable class="parameter">ftype</replaceable> [, ...]])
|
|
|
|
RETURNS <replaceable class="parameter">rtype</replaceable>
|
|
|
|
AS <replaceable class="parameter">path</replaceable>
|
|
|
|
LANGUAGE '<replaceable class="parameter">langname</replaceable>'
|
|
|
|
</SYNOPSIS>
|
|
|
|
|
|
|
|
<REFSECT2 ID="R2-SQL-CREATEFUNCTION-1">
|
|
|
|
<REFSECT2INFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSECT2INFO>
|
|
|
|
<TITLE>
|
|
|
|
Inputs
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
</PARA>
|
|
|
|
<VARIABLELIST>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
<VARIABLELIST>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<replaceable class="parameter">name</replaceable>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
The name of a function to create.
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<replaceable class="parameter">ftype</replaceable>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
The data type of function arguments.
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<replaceable class="parameter">rtype</replaceable>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
The return data type.
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<replaceable class="parameter">path</replaceable>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
May be either an SQL-query or an absolute path to an
|
|
|
|
object file.
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<replaceable class="parameter">langname</replaceable>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
may be '<literal>c</literal>', '<literal>sql</literal>', '<literal>internal</literal>' or '<replaceable class="parameter">plname</replaceable>'.
|
|
|
|
(where '<replaceable class="parameter">plname</replaceable>' is the language name of a created procedural
|
|
|
|
language. See <command>CREATE LANGUAGE</command> for details).
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
</variablelist>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
</VARIABLELIST>
|
|
|
|
</REFSECT2>
|
|
|
|
|
|
|
|
<REFSECT2 ID="R2-SQL-CREATEFUNCTION-2">
|
|
|
|
<REFSECT2INFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSECT2INFO>
|
|
|
|
<TITLE>
|
|
|
|
Outputs
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
</PARA>
|
|
|
|
<VARIABLELIST>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
<VARIABLELIST>
|
|
|
|
<VARLISTENTRY>
|
|
|
|
<TERM>
|
|
|
|
<ReturnValue>CREATE</ReturnValue>
|
|
|
|
</TERM>
|
|
|
|
<LISTITEM>
|
|
|
|
<PARA>
|
|
|
|
This is returned if the command completes successfully.
|
|
|
|
</PARA>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
</variablelist>
|
|
|
|
</LISTITEM>
|
|
|
|
</VARLISTENTRY>
|
|
|
|
</VARIABLELIST>
|
|
|
|
</REFSECT2>
|
|
|
|
</REFSYNOPSISDIV>
|
|
|
|
|
|
|
|
<REFSECT1 ID="R1-SQL-CREATEFUNCTION-1">
|
|
|
|
<REFSECT1INFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSECT1INFO>
|
|
|
|
<TITLE>
|
|
|
|
Description
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
With this command, a PostgreSQL user can register a function
|
|
|
|
with PostgreSQL. Subsequently, this user is treated as the
|
|
|
|
owner of the function.
|
|
|
|
</PARA>
|
|
|
|
|
|
|
|
<REFSECT2 ID="R2-SQL-CREATEFUNCTION-3">
|
|
|
|
<REFSECT2INFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSECT2INFO>
|
|
|
|
<TITLE>
|
|
|
|
Notes
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
Refer to <citetitle>PostgreSQL User's Guide</citetitle> chapter 6 for further information.
|
|
|
|
<comment>This reference needs to be corrected.</comment>
|
|
|
|
</PARA>
|
|
|
|
<PARA>
|
|
|
|
Refer to the <citerefentry>
|
|
|
|
<refentrytitle>DROP FUNCTION</refentrytitle>
|
|
|
|
</citerefentry> statement to drop functions.
|
|
|
|
</PARA>
|
|
|
|
</REFSECT2>
|
|
|
|
|
|
|
|
<REFSECT1 ID="R1-SQL-CREATEFUNCTION-2">
|
|
|
|
<TITLE>
|
|
|
|
Usage
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
To create a simple SQL function:
|
|
|
|
</PARA>
|
|
|
|
<ProgramListing>
|
|
|
|
CREATE FUNCTION one() RETURNS int4
|
|
|
|
AS 'SELECT 1 AS RESULT'
|
|
|
|
LANGUAGE 'sql';
|
|
|
|
|
|
|
|
SELECT one() AS answer;
|
|
|
|
|
|
|
|
<computeroutput>answer
|
|
|
|
------
|
|
|
|
1 </computeroutput>
|
|
|
|
</ProgramListing>
|
|
|
|
<para>
|
|
|
|
To create a C function, calling a routine from a user-created
|
|
|
|
shared library. This particular routine calculates a check
|
|
|
|
digit and returns TRUE if the check digit in the function parameters
|
|
|
|
is correct. It is intended for use in a CHECK contraint.
|
|
|
|
</para>
|
|
|
|
<programlisting>
|
|
|
|
<userinput>CREATE FUNCTION ean_checkdigit(bpchar, bpchar) RETURNS bool
|
|
|
|
AS '/usr1/proj/bray/sql/funcs.so' LANGUAGE 'c';
|
|
|
|
|
|
|
|
CREATE TABLE product
|
|
|
|
(
|
|
|
|
id char(8) PRIMARY KEY,
|
|
|
|
eanprefix char(8) CHECK (eanprefix ~ '[0-9]{2}-[0-9]{5}')
|
|
|
|
REFERENCES brandname(ean_prefix),
|
|
|
|
eancode char(6) CHECK (eancode ~ '[0-9]{6}'),
|
|
|
|
CONSTRAINT ean CHECK (ean_checkdigit(eanprefix, eancode))
|
|
|
|
);</userinput>
|
|
|
|
</programlisting>
|
|
|
|
</REFSECT1>
|
|
|
|
|
|
|
|
<REFSECT1 ID="R1-SQL-CREATEFUNCTION-3">
|
|
|
|
<TITLE>
|
|
|
|
Bugs
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
A C function cannot return a set of values.
|
|
|
|
</PARA>
|
|
|
|
</REFSECT1>
|
|
|
|
|
|
|
|
<REFSECT1 ID="R1-SQL-CREATEFUNCTION-4">
|
|
|
|
<TITLE>
|
|
|
|
Compatibility
|
|
|
|
</TITLE>
|
|
|
|
<PARA>
|
|
|
|
The CREATE FUNCTION statement is a PostgreSQL language extension.
|
|
|
|
</PARA>
|
|
|
|
|
|
|
|
<REFSECT2 ID="R2-SQL-CREATEFUNCTION-4">
|
|
|
|
<REFSECT2INFO>
|
|
|
|
<DATE>1998-04-15</DATE>
|
|
|
|
</REFSECT2INFO>
|
|
|
|
<TITLE>
|
|
|
|
SQL/PSM<footnote>
|
|
|
|
<para>
|
|
|
|
PSM stands for Persistent Stored Modules, it is a procedural
|
|
|
|
language and it was originally hoped that PSM would be ratified
|
|
|
|
as an official standard by late 1996. However PSM will
|
|
|
|
eventually become a standard.
|
|
|
|
</para>
|
|
|
|
</footnote>
|
|
|
|
</TITLE>
|
|
|
|
<para>
|
|
|
|
The SQL/PSM CREATE FUNCTION statement has the following syntax:
|
|
|
|
<programlisting>
|
|
|
|
CREATE FUNCTION <replaceable class="parameter">name</replaceable>
|
|
|
|
( [ [IN|OUT|INOUT] <replaceable class="parameter">parm</replaceable> <replaceable class="parameter">type</replaceable> [, ...] ])
|
|
|
|
RETURNS <replaceable class="parameter">rtype</replaceable>
|
|
|
|
LANGUAGE '<replaceable class="parameter">langname</replaceable>'
|
|
|
|
ESPECIFIC <replaceable class="parameter">routine</replaceable>
|
|
|
|
<replaceable class="parameter">SQL-statement</replaceable>
|
|
|
|
</programlisting>
|
|
|
|
</para>
|
|
|
|
</refsect2>
|
|
|
|
</refsect1>
|
|
|
|
</REFENTRY>
|
|
|
|
|
|
|
|
|
|
|
|
<!-- Keep this comment at the end of the file
|
|
|
|
Local variables:
|
|
|
|
mode: sgml
|
|
|
|
sgml-omittag:t
|
|
|
|
sgml-shorttag:t
|
|
|
|
sgml-minimize-attributes:nil
|
|
|
|
sgml-always-quote-attributes:t
|
|
|
|
sgml-indent-step:1
|
|
|
|
sgml-indent-data:t
|
|
|
|
sgml-parent-document:nil
|
|
|
|
sgml-default-dtd-file:"../reference.ced"
|
|
|
|
sgml-exposed-tags:nil
|
|
|
|
sgml-local-catalogs:"/usr/lib/sgml/catalog"
|
|
|
|
sgml-local-ecat-files:nil
|
|
|
|
End:
|
|
|
|
-->
|