117 lines
2.8 KiB
Plaintext
117 lines
2.8 KiB
Plaintext
<!--
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doc/src/sgml/ref/drop_type.sgml
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PostgreSQL documentation
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-->
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<refentry id="sql-droptype">
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<indexterm zone="sql-droptype">
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<primary>DROP TYPE</primary>
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</indexterm>
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<refmeta>
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<refentrytitle>DROP TYPE</refentrytitle>
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<manvolnum>7</manvolnum>
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<refmiscinfo>SQL - Language Statements</refmiscinfo>
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</refmeta>
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<refnamediv>
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<refname>DROP TYPE</refname>
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<refpurpose>remove a data type</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<synopsis>
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DROP TYPE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
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</synopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>
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<command>DROP TYPE</command> removes a user-defined data type.
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Only the owner of a type can remove it.
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</para>
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</refsect1>
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<refsect1>
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<title>Parameters</title>
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<variablelist>
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<varlistentry>
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<term><literal>IF EXISTS</literal></term>
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<listitem>
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<para>
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Do not throw an error if the type does not exist. A notice is issued
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in this case.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><replaceable class="parameter">name</replaceable></term>
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<listitem>
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<para>
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The name (optionally schema-qualified) of the data type to remove.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>CASCADE</literal></term>
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<listitem>
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<para>
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Automatically drop objects that depend on the type (such as
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table columns, functions, and operators),
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and in turn all objects that depend on those objects
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(see <xref linkend="ddl-depend"/>).
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><literal>RESTRICT</literal></term>
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<listitem>
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<para>
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Refuse to drop the type if any objects depend on it. This is
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the default.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1 id="sql-droptype-examples">
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<title>Examples</title>
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<para>
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To remove the data type <type>box</type>:
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<programlisting>
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DROP TYPE box;
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</programlisting></para>
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</refsect1>
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<refsect1 id="sql-droptype-compatibility">
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<title>Compatibility</title>
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<para>
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This command is similar to the corresponding command in the SQL
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standard, apart from the <literal>IF EXISTS</literal>
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option, which is a <productname>PostgreSQL</productname> extension.
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But note that much of the <command>CREATE TYPE</command> command
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and the data type extension mechanisms in
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<productname>PostgreSQL</productname> differ from the SQL standard.
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</para>
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</refsect1>
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<refsect1 id="sql-droptype-see-also">
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<title>See Also</title>
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<simplelist type="inline">
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<member><xref linkend="sql-altertype"/></member>
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<member><xref linkend="sql-createtype"/></member>
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</simplelist>
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</refsect1>
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</refentry>
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