1<!-- 2doc/src/sgml/ref/drop_cast.sgml 3PostgreSQL documentation 4--> 5 6<refentry id="SQL-DROPCAST"> 7 <indexterm zone="sql-dropcast"> 8 <primary>DROP CAST</primary> 9 </indexterm> 10 11 <refmeta> 12 <refentrytitle>DROP CAST</refentrytitle> 13 <manvolnum>7</manvolnum> 14 <refmiscinfo>SQL - Language Statements</refmiscinfo> 15 </refmeta> 16 17 <refnamediv> 18 <refname>DROP CAST</refname> 19 <refpurpose>remove a cast</refpurpose> 20 </refnamediv> 21 22 <refsynopsisdiv> 23<synopsis> 24DROP CAST [ IF EXISTS ] (<replaceable>source_type</replaceable> AS <replaceable>target_type</replaceable>) [ CASCADE | RESTRICT ] 25</synopsis> 26 </refsynopsisdiv> 27 28 <refsect1 id="sql-dropcast-description"> 29 <title>Description</title> 30 31 <para> 32 <command>DROP CAST</command> removes a previously defined cast. 33 </para> 34 35 <para> 36 To be able to drop a cast, you must own the source or the target 37 data type. These are the same privileges that are required to 38 create a cast. 39 </para> 40 </refsect1> 41 42 <refsect1> 43 <title>Parameters</title> 44 45 <variablelist> 46 47 <varlistentry> 48 <term><literal>IF EXISTS</literal></term> 49 <listitem> 50 <para> 51 Do not throw an error if the cast does not exist. A notice is issued 52 in this case. 53 </para> 54 </listitem> 55 </varlistentry> 56 57 <varlistentry> 58 <term><replaceable>source_type</replaceable></term> 59 60 <listitem> 61 <para> 62 The name of the source data type of the cast. 63 </para> 64 </listitem> 65 </varlistentry> 66 67 <varlistentry> 68 <term><replaceable>target_type</replaceable></term> 69 70 <listitem> 71 <para> 72 The name of the target data type of the cast. 73 </para> 74 </listitem> 75 </varlistentry> 76 77 <varlistentry> 78 <term><literal>CASCADE</literal></term> 79 <term><literal>RESTRICT</literal></term> 80 81 <listitem> 82 <para> 83 These key words do not have any effect, since there are no 84 dependencies on casts. 85 </para> 86 </listitem> 87 </varlistentry> 88 </variablelist> 89 </refsect1> 90 91 <refsect1 id="sql-dropcast-examples"> 92 <title>Examples</title> 93 94 <para> 95 To drop the cast from type <type>text</type> to type <type>int</type>: 96<programlisting> 97DROP CAST (text AS int); 98</programlisting></para> 99 </refsect1> 100 101 <refsect1 id="sql-dropcast-compat"> 102 <title>Compatibility</title> 103 104 <para> 105 The <command>DROP CAST</command> command conforms to the SQL standard. 106 </para> 107 </refsect1> 108 109 <refsect1> 110 <title>See Also</title> 111 112 <simplelist type="inline"> 113 <member><xref linkend="sql-createcast"></member> 114 </simplelist> 115 </refsect1> 116 117</refentry> 118