232 lines
7.2 KiB
Plaintext
232 lines
7.2 KiB
Plaintext
<!--
|
|
doc/src/sgml/ref/drop_procedure.sgml
|
|
PostgreSQL documentation
|
|
-->
|
|
|
|
<refentry id="sql-dropprocedure">
|
|
<indexterm zone="sql-dropprocedure">
|
|
<primary>DROP PROCEDURE</primary>
|
|
</indexterm>
|
|
|
|
<refmeta>
|
|
<refentrytitle>DROP PROCEDURE</refentrytitle>
|
|
<manvolnum>7</manvolnum>
|
|
<refmiscinfo>SQL - Language Statements</refmiscinfo>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>DROP PROCEDURE</refname>
|
|
<refpurpose>remove a procedure</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<synopsis>
|
|
DROP PROCEDURE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] [, ...]
|
|
[ CASCADE | RESTRICT ]
|
|
</synopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>
|
|
<command>DROP PROCEDURE</command> removes the definition of one or more
|
|
existing procedures. To execute this command the user must be the
|
|
owner of the procedure(s). The argument types to the
|
|
procedure(s) usually must be specified, since several different procedures
|
|
can exist with the same name and different argument lists.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Parameters</title>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><literal>IF EXISTS</literal></term>
|
|
<listitem>
|
|
<para>
|
|
Do not throw an error if the procedure does not exist. A notice is issued
|
|
in this case.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">name</replaceable></term>
|
|
<listitem>
|
|
<para>
|
|
The name (optionally schema-qualified) of an existing procedure.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">argmode</replaceable></term>
|
|
|
|
<listitem>
|
|
<para>
|
|
The mode of an argument: <literal>IN</literal>, <literal>OUT</literal>,
|
|
<literal>INOUT</literal>, or <literal>VARIADIC</literal>. If omitted,
|
|
the default is <literal>IN</literal> (but see below).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">argname</replaceable></term>
|
|
|
|
<listitem>
|
|
<para>
|
|
The name of an argument.
|
|
Note that <command>DROP PROCEDURE</command> does not actually pay
|
|
any attention to argument names, since only the argument data
|
|
types are used to determine the procedure's identity.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><replaceable class="parameter">argtype</replaceable></term>
|
|
|
|
<listitem>
|
|
<para>
|
|
The data type(s) of the procedure's arguments (optionally
|
|
schema-qualified), if any.
|
|
See below for details.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>CASCADE</literal></term>
|
|
<listitem>
|
|
<para>
|
|
Automatically drop objects that depend on the procedure,
|
|
and in turn all objects that depend on those objects
|
|
(see <xref linkend="ddl-depend"/>).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>RESTRICT</literal></term>
|
|
<listitem>
|
|
<para>
|
|
Refuse to drop the procedure if any objects depend on it. This
|
|
is the default.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1 id="sql-dropprocedure-notes">
|
|
<title>Notes</title>
|
|
|
|
<para>
|
|
If there is only one procedure of the given name, the argument list
|
|
can be omitted. Omit the parentheses too in this case.
|
|
</para>
|
|
|
|
<para>
|
|
In <productname>PostgreSQL</productname>, it's sufficient to list the
|
|
input (including <literal>INOUT</literal>) arguments,
|
|
because no two routines of the same name are allowed to share the same
|
|
input-argument list. Moreover, the <command>DROP</command> command
|
|
will not actually check that you wrote the types
|
|
of <literal>OUT</literal> arguments correctly; so any arguments that
|
|
are explicitly marked <literal>OUT</literal> are just noise. But
|
|
writing them is recommendable for consistency with the
|
|
corresponding <command>CREATE</command> command.
|
|
</para>
|
|
|
|
<para>
|
|
For compatibility with the SQL standard, it is also allowed to write
|
|
all the argument data types (including those of <literal>OUT</literal>
|
|
arguments) without
|
|
any <replaceable class="parameter">argmode</replaceable> markers.
|
|
When this is done, the types of the procedure's <literal>OUT</literal>
|
|
argument(s) <emphasis>will</emphasis> be verified against the command.
|
|
This provision creates an ambiguity, in that when the argument list
|
|
contains no <replaceable class="parameter">argmode</replaceable>
|
|
markers, it's unclear which rule is intended.
|
|
The <command>DROP</command> command will attempt the lookup both ways,
|
|
and will throw an error if two different procedures are found.
|
|
To avoid the risk of such ambiguity, it's recommendable to
|
|
write <literal>IN</literal> markers explicitly rather than letting them
|
|
be defaulted, thus forcing the
|
|
traditional <productname>PostgreSQL</productname> interpretation to be
|
|
used.
|
|
</para>
|
|
|
|
<para>
|
|
The lookup rules just explained are also used by other commands that
|
|
act on existing procedures, such as <command>ALTER PROCEDURE</command>
|
|
and <command>COMMENT ON PROCEDURE</command>.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1 id="sql-dropprocedure-examples">
|
|
<title>Examples</title>
|
|
|
|
<para>
|
|
If there is only one procedure <literal>do_db_maintenance</literal>,
|
|
this command is sufficient to drop it:
|
|
<programlisting>
|
|
DROP PROCEDURE do_db_maintenance;
|
|
</programlisting>
|
|
</para>
|
|
|
|
<para>
|
|
Given this procedure definition:
|
|
<programlisting>
|
|
CREATE PROCEDURE do_db_maintenance(IN target_schema text, OUT results text) ...
|
|
</programlisting>
|
|
any one of these commands would work to drop it:
|
|
<programlisting>
|
|
DROP PROCEDURE do_db_maintenance(IN target_schema text, OUT results text);
|
|
DROP PROCEDURE do_db_maintenance(IN text, OUT text);
|
|
DROP PROCEDURE do_db_maintenance(IN text);
|
|
DROP PROCEDURE do_db_maintenance(text);
|
|
DROP PROCEDURE do_db_maintenance(text, text); -- potentially ambiguous
|
|
</programlisting>
|
|
However, the last example would be ambiguous if there is also, say,
|
|
<programlisting>
|
|
CREATE PROCEDURE do_db_maintenance(IN target_schema text, IN options text) ...
|
|
</programlisting></para>
|
|
</refsect1>
|
|
|
|
<refsect1 id="sql-dropprocedure-compatibility">
|
|
<title>Compatibility</title>
|
|
|
|
<para>
|
|
This command conforms to the SQL standard, with
|
|
these <productname>PostgreSQL</productname> extensions:
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The standard only allows one procedure to be dropped per command.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>The <literal>IF EXISTS</literal> option is an extension.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>The ability to specify argument modes and names is an
|
|
extension, and the lookup rules differ when modes are given.</para>
|
|
</listitem>
|
|
</itemizedlist></para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<simplelist type="inline">
|
|
<member><xref linkend="sql-createprocedure"/></member>
|
|
<member><xref linkend="sql-alterprocedure"/></member>
|
|
<member><xref linkend="sql-dropfunction"/></member>
|
|
<member><xref linkend="sql-droproutine"/></member>
|
|
</simplelist>
|
|
</refsect1>
|
|
|
|
</refentry>
|