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

More minor updates and copy-editing.

Browse Source
This commit is contained in:
Tom Lane
2005-01-04 00:39:53 +00:00
parent 246be304a5
commit 4e94ea9fc9
37 changed files with 571 additions and 413 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
doc/src/sgml/ref/create_function.sgml
View File

@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.63 2004/11/27 21:27:07 petere Exp $
$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.64 2005/01/04 00:39:53 tgl Exp $
-->
<refentry id="SQL-CREATEFUNCTION">
@ -62,8 +62,8 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<para>
If you drop and then recreate a function, the new function is not
the same entity as the old; you will break existing rules, views,
triggers, etc. that referred to the old function. Use
the same entity as the old; you will have to drop existing rules, views,
triggers, etc. that refer to the old function. Use
<command>CREATE OR REPLACE FUNCTION</command> to change a function
definition without breaking objects that refer to the function.
</para>
@ -106,16 +106,8 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<listitem>
<para>
The data type(s) of the function's arguments (optionally
schema-qualified), if any. The argument types may be base, complex, or
domains, or copy the type of an existing column.
</para>
<para>
The type of a column is referenced by writing
<literal><replaceable
class="parameter">tablename</replaceable>.<replaceable
class="parameter">columnname</replaceable>%TYPE</literal>;
using this can sometimes help make a function independent from
changes to the definition of a table.
schema-qualified), if any. The argument types may be base, composite,
or domain types, or may reference the type of a table column.
</para>
<para>
Depending on the implementation language it may also be allowed
@ -123,6 +115,14 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
Pseudotypes indicate that the actual argument type is either
incompletely specified, or outside the set of ordinary SQL data types.
</para>
<para>
The type of a column is referenced by writing
<literal><replaceable
class="parameter">tablename</replaceable>.<replaceable
class="parameter">columnname</replaceable>%TYPE</literal>.
Using this feature can sometimes help make a function independent of
changes to the definition of a table.
</para>
</listitem>
</varlistentry>
@ -132,18 +132,22 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<listitem>
<para>
The return data type (optionally schema-qualified). The return type
may be a base type, complex type, or a domain,
or may be specified to copy the type of an existing column. See the description
under <literal>argtype</literal> above on how to reference the type
of an existing column.
</para>
<para>
may be a base, composite, or domain type,
or may reference the type of a table column.
Depending on the implementation language it may also be allowed
to specify <quote>pseudotypes</> such as <type>cstring</>.
</para>
<para>
The <literal>SETOF</literal>
modifier indicates that the function will return a set of
items, rather than a single item.
</para>
<para>
The type of a column is referenced by writing
<literal><replaceable
class="parameter">tablename</replaceable>.<replaceable
class="parameter">columnname</replaceable>%TYPE</literal>.
</para>
</listitem>
</varlistentry>
@ -155,8 +159,7 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
The name of the language that the function is implemented in.
May be <literal>SQL</literal>, <literal>C</literal>,
<literal>internal</literal>, or the name of a user-defined
procedural language. (See also <xref linkend="app-createlang"
endterm="app-createlang-title">.) For backward compatibility,
procedural language. For backward compatibility,
the name may be enclosed by single quotes.
</para>
</listitem>
@ -303,7 +306,7 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<term><literal>isStrict</></term>
<listitem>
<para>
Equivalent to <literal>STRICT</literal> or <literal>RETURNS NULL ON NULL INPUT</literal>
Equivalent to <literal>STRICT</literal> or <literal>RETURNS NULL ON NULL INPUT</literal>.
</para>
</listitem>
</varlistentry>
@ -394,7 +397,7 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
information and examples, see <xref linkend="xfunc">.
<programlisting>
CREATE FUNCTION add(integer, integer) RETURNS integer
AS $$select $1 + $2;$$
AS 'select $1 + $2;'
LANGUAGE SQL
IMMUTABLE
RETURNS NULL ON NULL INPUT;
@ -406,10 +409,11 @@ CREATE FUNCTION add(integer, integer) RETURNS integer
<application>PL/pgSQL</application>:
<programlisting>
CREATE OR REPLACE FUNCTION increment(i integer) RETURNS integer AS '
CREATE OR REPLACE FUNCTION increment(i integer) RETURNS integer AS $$
BEGIN
RETURN i + 1;
END;' LANGUAGE plpgsql;
END;
$$ LANGUAGE plpgsql;
</programlisting>
</para>
</refsect1>
@ -427,17 +431,17 @@ CREATE OR REPLACE FUNCTION increment(i integer) RETURNS integer AS '
</refsect1>
<refsect1 id="sql-createfunction-seealso">
<refsect1>
<title>See Also</title>
<para>
<xref linkend="sql-alterfunction" endterm="sql-alterfunction-title">,
<xref linkend="sql-dropfunction" endterm="sql-dropfunction-title">,
<xref linkend="sql-grant" endterm="sql-grant-title">,
<xref linkend="sql-load" endterm="sql-load-title">,
<xref linkend="sql-revoke" endterm="sql-revoke-title">,
<xref linkend="app-createlang">
</para>
<simplelist type="inline">
<member><xref linkend="sql-alterfunction" endterm="sql-alterfunction-title"></member>
<member><xref linkend="sql-dropfunction" endterm="sql-dropfunction-title"></member>
<member><xref linkend="sql-grant" endterm="sql-grant-title"></member>
<member><xref linkend="sql-load" endterm="sql-load-title"></member>
<member><xref linkend="sql-revoke" endterm="sql-revoke-title"></member>
<member><xref linkend="app-createlang" endterm="app-createlang-title"></member>
</simplelist>
</refsect1>
</refentry>