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diff --git a/doc/src/sgml/ref/drop_function.sgml b/doc/src/sgml/ref/drop_function.sgml new file mode 100644 index 0000000..d84bebc --- /dev/null +++ b/doc/src/sgml/ref/drop_function.sgml @@ -0,0 +1,192 @@ +<!-- +doc/src/sgml/ref/drop_function.sgml +PostgreSQL documentation +--> + +<refentry id="sql-dropfunction"> + <indexterm zone="sql-dropfunction"> + <primary>DROP FUNCTION</primary> + </indexterm> + + <refmeta> + <refentrytitle>DROP FUNCTION</refentrytitle> + <manvolnum>7</manvolnum> + <refmiscinfo>SQL - Language Statements</refmiscinfo> + </refmeta> + + <refnamediv> + <refname>DROP FUNCTION</refname> + <refpurpose>remove a function</refpurpose> + </refnamediv> + + <refsynopsisdiv> +<synopsis> +DROP FUNCTION [ 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 FUNCTION</command> removes the definition of an existing + function. To execute this command the user must be the + owner of the function. The argument types to the + function must be specified, since several different functions + 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 function 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 function. If no + argument list is specified, the name must be unique in its schema. + </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>. + Note that <command>DROP FUNCTION</command> does not actually pay + any attention to <literal>OUT</literal> arguments, since only the input + arguments are needed to determine the function's identity. + So it is sufficient to list the <literal>IN</literal>, <literal>INOUT</literal>, + and <literal>VARIADIC</literal> arguments. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">argname</replaceable></term> + + <listitem> + <para> + The name of an argument. + Note that <command>DROP FUNCTION</command> does not actually pay + any attention to argument names, since only the argument data + types are needed to determine the function's identity. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="parameter">argtype</replaceable></term> + + <listitem> + <para> + The data type(s) of the function's arguments (optionally + schema-qualified), if any. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>CASCADE</literal></term> + <listitem> + <para> + Automatically drop objects that depend on the function (such as + operators or triggers), + 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 function if any objects depend on it. This + is the default. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1 id="sql-dropfunction-examples"> + <title>Examples</title> + + <para> + This command removes the square root function: + +<programlisting> +DROP FUNCTION sqrt(integer); +</programlisting></para> + + <para> + Drop multiple functions in one command: +<programlisting> +DROP FUNCTION sqrt(integer), sqrt(bigint); +</programlisting></para> + + <para> + If the function name is unique in its schema, it can be referred to without + an argument list: +<programlisting> +DROP FUNCTION update_employee_salaries; +</programlisting> + Note that this is different from +<programlisting> +DROP FUNCTION update_employee_salaries(); +</programlisting> + which refers to a function with zero arguments, whereas the first variant + can refer to a function with any number of arguments, including zero, as + long as the name is unique. + </para> + </refsect1> + + <refsect1 id="sql-dropfunction-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 function to be dropped per command.</para> + </listitem> + <listitem> + <para>The <literal>IF EXISTS</literal> option</para> + </listitem> + <listitem> + <para>The ability to specify argument modes and names</para> + </listitem> + </itemizedlist></para> + </refsect1> + + <refsect1> + <title>See Also</title> + + <simplelist type="inline"> + <member><xref linkend="sql-createfunction"/></member> + <member><xref linkend="sql-alterfunction"/></member> + <member><xref linkend="sql-dropprocedure"/></member> + <member><xref linkend="sql-droproutine"/></member> + </simplelist> + </refsect1> + +</refentry> |