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diff --git a/doc/src/sgml/ref/alter_foreign_table.sgml b/doc/src/sgml/ref/alter_foreign_table.sgml new file mode 100644 index 00000000000..9d14b195809 --- /dev/null +++ b/doc/src/sgml/ref/alter_foreign_table.sgml @@ -0,0 +1,315 @@ +<!-- +doc/src/sgml/rel/alter_foreign_table.sgml +PostgreSQL documentation +--> + +<refentry id="SQL-ALTERFOREIGNTABLE"> + <refmeta> + <refentrytitle>ALTER FOREIGN TABLE</refentrytitle> + <manvolnum>7</manvolnum> + <refmiscinfo>SQL - Language Statements</refmiscinfo> + </refmeta> + + <refnamediv> + <refname>ALTER FOREIGN TABLE</refname> + <refpurpose>change the definition of a foreign table</refpurpose> + </refnamediv> + + <indexterm zone="sql-alterforeigntable"> + <primary>ALTER FOREIGN TABLE</primary> + </indexterm> + + <refsynopsisdiv> +<synopsis> +ALTER FOREIGN TABLE <replaceable class="PARAMETER">name</replaceable> + <replaceable class="PARAMETER">action</replaceable> [, ... ] +ALTER FOREIGN TABLE <replaceable class="PARAMETER">name</replaceable> + RENAME [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> TO <replaceable class="PARAMETER">new_column</replaceable> +ALTER FOREIGN TABLE <replaceable class="PARAMETER">name</replaceable> + RENAME TO <replaceable class="PARAMETER">new_name</replaceable> +ALTER FOREIGN TABLE <replaceable class="PARAMETER">name</replaceable> + SET SCHEMA <replaceable class="PARAMETER">new_schema</replaceable> + +<phrase>where <replaceable class="PARAMETER">action</replaceable> is one of:</phrase> + + ADD [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> <replaceable class="PARAMETER">type</replaceable> + DROP [ COLUMN ] [ IF EXISTS ] <replaceable class="PARAMETER">column</replaceable> [ RESTRICT | CASCADE ] + ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> [ SET DATA ] TYPE <replaceable class="PARAMETER">type</replaceable> + ALTER [ COLUMN ] <replaceable class="PARAMETER">column</replaceable> { SET | DROP } NOT NULL + OWNER TO <replaceable class="PARAMETER">new_owner</replaceable> + OPTIONS ( [ ADD | SET | DROP ] <replaceable class="PARAMETER">option</replaceable> ['<replaceable class="PARAMETER">value</replaceable>'] [, ... ]) +</synopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para> + <command>ALTER FOREIGN TABLE</command> changes the definition of an + existing foreign table. There are several subforms: + + <variablelist> + <varlistentry> + <term><literal>ADD COLUMN</literal></term> + <listitem> + <para> + This form adds a new column to the foreign table, using the same syntax as + <xref linkend="SQL-CREATEFOREIGNTABLE">. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>DROP COLUMN [ IF EXISTS ]</literal></term> + <listitem> + <para> + This form drops a column from a foreign table. + You will need to say <literal>CASCADE</> if + anything outside the table depends on the column; for example, + views. + If <literal>IF EXISTS</literal> is specified and the column + does not exist, no error is thrown. In this case a notice + is issued instead. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET DATA TYPE</literal></term> + <listitem> + <para> + This form changes the type of a column of a foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET</literal>/<literal>DROP NOT NULL</literal></term> + <listitem> + <para> + Mark a column as allowing, or not allowing, null values. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>OWNER</literal></term> + <listitem> + <para> + This form changes the owner of the foreign table to the + specified user. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>RENAME</literal></term> + <listitem> + <para> + The <literal>RENAME</literal> forms change the name of a foreign table + or the name of an individual column in a foreign table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>SET SCHEMA</literal></term> + <listitem> + <para> + This form moves the foreign table into another schema. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>OPTIONS ( [ ADD | SET | DROP ] <replaceable class="PARAMETER">option</replaceable> ['<replaceable class="PARAMETER">value</replaceable>'] [, ... ] )</literal></term> + <listitem> + <para> + Change options for the foreign table or the column of the foreign table. + <literal>ADD</>, <literal>SET</>, and <literal>DROP</> + specify the action to be performed. <literal>ADD</> is assumed + if no operation is explicitly specified. Option names must be + unique; names and values are also validated using the foreign + data wrapper library. + </para> + </listitem> + </varlistentry> + + </variablelist> + </para> + + <para> + All the actions except <literal>RENAME</literal> and <literal>SET SCHEMA</> + can be combined into + a list of multiple alterations to apply in parallel. For example, it + is possible to add several columns and/or alter the type of several + columns in a single command. + </para> + + <para> + You must own the table to use <command>ALTER FOREIGN TABLE</>. + To change the schema of a foreign table, you must also have + <literal>CREATE</literal> privilege on the new schema. + To add the table as a new child of a parent table, you must own the + parent table as well. + To alter the owner, you must also be a direct or indirect member of the new + owning role, and that role must have <literal>CREATE</literal> privilege on + the table's schema. (These restrictions enforce that altering the owner + doesn't do anything you couldn't do by dropping and recreating the table. + However, a superuser can alter ownership of any table anyway.) + </para> + </refsect1> + + <refsect1> + <title>Parameters</title> + + <variablelist> + + <varlistentry> + <term><replaceable class="PARAMETER">name</replaceable></term> + <listitem> + <para> + The name (possibly schema-qualified) of an existing foreign table to + alter. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">column</replaceable></term> + <listitem> + <para> + Name of a new or existing column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">new_column</replaceable></term> + <listitem> + <para> + New name for an existing column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">new_name</replaceable></term> + <listitem> + <para> + New name for the table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">type</replaceable></term> + <listitem> + <para> + Data type of the new column, or new data type for an existing + column. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>CASCADE</literal></term> + <listitem> + <para> + Automatically drop objects that depend on the dropped column + (for example, views referencing the column). + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><literal>RESTRICT</literal></term> + <listitem> + <para> + Refuse to drop the column if there are any dependent + objects. This is the default behavior. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">new_owner</replaceable></term> + <listitem> + <para> + The user name of the new owner of the table. + </para> + </listitem> + </varlistentry> + + <varlistentry> + <term><replaceable class="PARAMETER">new_schema</replaceable></term> + <listitem> + <para> + The name of the schema to which the table will be moved. + </para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para> + The key word <literal>COLUMN</literal> is noise and can be omitted. + </para> + + <para> + Consistency with the foreign server is not checked when a column is + added or removed with <literal>ADD COLUMN</literal> or + <literal>DROP COLUMN</literal>, a system <literal>oid</> column is added + or removed, a <literal>CHECK</> or <literal>NOT NULL</> constraint is + added, or column type is changed with <literal>ALTER TYPE</>. It is the + user's responsibility to ensure that the table definition matches the + remote side. + </para> + + <para> + Refer to <xref linkend="sql-createforeigntable"> for a further description of valid + parameters. + </para> + </refsect1> + + <refsect1> + <title>Examples</title> + + <para> + To mark a column as not-null: +<programlisting> +ALTER FOREIGN TABLE distributors ALTER COLUMN street SET NOT NULL; +</programlisting> + </para> + + <para> + To change options of a foreign table: +<programlisting> +ALTER FOREIGN TABLE myschema.distributors OPTIONS (ADD opt1 'value', SET opt2, 'value2', DROP opt3 'value3'); +</programlisting> + </para> + + </refsect1> + + <refsect1> + <title>Compatibility</title> + + <para> + The forms <literal>ADD</literal>, <literal>DROP</>, + and <literal>SET DATA TYPE</literal> + conform with the SQL standard. The other forms are + <productname>PostgreSQL</productname> extensions of the SQL standard. + Also, the ability to specify more than one manipulation in a single + <command>ALTER FOREIGN TABLE</> command is an extension. + </para> + + <para> + <command>ALTER FOREIGN TABLE DROP COLUMN</> can be used to drop the only + column of a foreign table, leaving a zero-column table. This is an + extension of SQL, which disallows zero-column foreign tables. + </para> + </refsect1> +</refentry> |