1<!-- 2doc/src/sgml/ref/alter_view.sgml 3PostgreSQL documentation 4--> 5 6<refentry id="sql-alterview"> 7 <indexterm zone="sql-alterview"> 8 <primary>ALTER VIEW</primary> 9 </indexterm> 10 11 <refmeta> 12 <refentrytitle>ALTER VIEW</refentrytitle> 13 <manvolnum>7</manvolnum> 14 <refmiscinfo>SQL - Language Statements</refmiscinfo> 15 </refmeta> 16 17 <refnamediv> 18 <refname>ALTER VIEW</refname> 19 <refpurpose>change the definition of a view</refpurpose> 20 </refnamediv> 21 22 <refsynopsisdiv> 23<synopsis> 24ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> SET DEFAULT <replaceable class="parameter">expression</replaceable> 25ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> ALTER [ COLUMN ] <replaceable class="parameter">column_name</replaceable> DROP DEFAULT 26ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_USER | SESSION_USER } 27ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> RENAME [ COLUMN ] <replaceable class="parameter">column_name</replaceable> TO <replaceable class="parameter">new_column_name</replaceable> 28ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable> 29ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable> 30ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> SET ( <replaceable class="parameter">view_option_name</replaceable> [= <replaceable class="parameter">view_option_value</replaceable>] [, ... ] ) 31ALTER VIEW [ IF EXISTS ] <replaceable class="parameter">name</replaceable> RESET ( <replaceable class="parameter">view_option_name</replaceable> [, ... ] ) 32</synopsis> 33 </refsynopsisdiv> 34 35 <refsect1> 36 <title>Description</title> 37 38 <para> 39 <command>ALTER VIEW</command> changes various auxiliary properties 40 of a view. (If you want to modify the view's defining query, 41 use <command>CREATE OR REPLACE VIEW</command>.) 42 </para> 43 44 <para> 45 You must own the view to use <command>ALTER VIEW</command>. 46 To change a view's schema, you must also have <literal>CREATE</literal> 47 privilege on the new schema. 48 To alter the owner, you must also be a direct or indirect member of the new 49 owning role, and that role must have <literal>CREATE</literal> privilege on 50 the view's schema. (These restrictions enforce that altering the owner 51 doesn't do anything you couldn't do by dropping and recreating the view. 52 However, a superuser can alter ownership of any view anyway.) 53 </para> 54 </refsect1> 55 56 <refsect1> 57 <title>Parameters</title> 58 59 <variablelist> 60 <varlistentry> 61 <term><replaceable class="parameter">name</replaceable></term> 62 <listitem> 63 <para> 64 The name (optionally schema-qualified) of an existing view. 65 </para> 66 </listitem> 67 </varlistentry> 68 69 <varlistentry> 70 <term><replaceable class="parameter">column_name</replaceable></term> 71 <listitem> 72 <para> 73 Name of an existing column. 74 </para> 75 </listitem> 76 </varlistentry> 77 78 <varlistentry> 79 <term><replaceable class="parameter">new_column_name</replaceable></term> 80 <listitem> 81 <para> 82 New name for an existing column. 83 </para> 84 </listitem> 85 </varlistentry> 86 87 <varlistentry> 88 <term><literal>IF EXISTS</literal></term> 89 <listitem> 90 <para> 91 Do not throw an error if the view does not exist. A notice is issued 92 in this case. 93 </para> 94 </listitem> 95 </varlistentry> 96 97 <varlistentry> 98 <term><literal>SET</literal>/<literal>DROP DEFAULT</literal></term> 99 <listitem> 100 <para> 101 These forms set or remove the default value for a column. 102 A view column's default value is substituted into any 103 <command>INSERT</command> or <command>UPDATE</command> command whose target is the 104 view, before applying any rules or triggers for the view. The view's 105 default will therefore take precedence over any default values from 106 underlying relations. 107 </para> 108 </listitem> 109 </varlistentry> 110 111 <varlistentry> 112 <term><replaceable class="parameter">new_owner</replaceable></term> 113 <listitem> 114 <para> 115 The user name of the new owner of the view. 116 </para> 117 </listitem> 118 </varlistentry> 119 120 <varlistentry> 121 <term><replaceable class="parameter">new_name</replaceable></term> 122 <listitem> 123 <para> 124 The new name for the view. 125 </para> 126 </listitem> 127 </varlistentry> 128 129 <varlistentry> 130 <term><replaceable class="parameter">new_schema</replaceable></term> 131 <listitem> 132 <para> 133 The new schema for the view. 134 </para> 135 </listitem> 136 </varlistentry> 137 138 <varlistentry> 139 <term><literal>SET ( <replaceable class="parameter">view_option_name</replaceable> [= <replaceable class="parameter">view_option_value</replaceable>] [, ... ] )</literal></term> 140 <term><literal>RESET ( <replaceable class="parameter">view_option_name</replaceable> [, ... ] )</literal></term> 141 <listitem> 142 <para> 143 Sets or resets a view option. Currently supported options are: 144 <variablelist> 145 <varlistentry> 146 <term><literal>check_option</literal> (<type>enum</type>)</term> 147 <listitem> 148 <para> 149 Changes the check option of the view. The value must 150 be <literal>local</literal> or <literal>cascaded</literal>. 151 </para> 152 </listitem> 153 </varlistentry> 154 <varlistentry> 155 <term><literal>security_barrier</literal> (<type>boolean</type>)</term> 156 <listitem> 157 <para> 158 Changes the security-barrier property of the view. The value must 159 be Boolean value, such as <literal>true</literal> 160 or <literal>false</literal>. 161 </para> 162 </listitem> 163 </varlistentry> 164 </variablelist></para> 165 </listitem> 166 </varlistentry> 167 </variablelist> 168 </refsect1> 169 170 <refsect1> 171 <title>Notes</title> 172 173 <para> 174 For historical reasons, <command>ALTER TABLE</command> can be used with 175 views too; but the only variants of <command>ALTER TABLE</command> 176 that are allowed with views are equivalent to the ones shown above. 177 </para> 178 </refsect1> 179 180 <refsect1> 181 <title>Examples</title> 182 183 <para> 184 To rename the view <literal>foo</literal> to 185 <literal>bar</literal>: 186<programlisting> 187ALTER VIEW foo RENAME TO bar; 188</programlisting> 189 </para> 190 191 <para> 192 To attach a default column value to an updatable view: 193<programlisting> 194CREATE TABLE base_table (id int, ts timestamptz); 195CREATE VIEW a_view AS SELECT * FROM base_table; 196ALTER VIEW a_view ALTER COLUMN ts SET DEFAULT now(); 197INSERT INTO base_table(id) VALUES(1); -- ts will receive a NULL 198INSERT INTO a_view(id) VALUES(2); -- ts will receive the current time 199</programlisting></para> 200 </refsect1> 201 202 <refsect1> 203 <title>Compatibility</title> 204 205 <para> 206 <command>ALTER VIEW</command> is a <productname>PostgreSQL</productname> 207 extension of the SQL standard. 208 </para> 209 </refsect1> 210 211 <refsect1> 212 <title>See Also</title> 213 214 <simplelist type="inline"> 215 <member><xref linkend="sql-createview"/></member> 216 <member><xref linkend="sql-dropview"/></member> 217 </simplelist> 218 </refsect1> 219</refentry> 220