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5f588e2005
Omit incorrect = sign, and properly document server_name parameter. Shigeru Hanada
198 lines
5.7 KiB
Plaintext
198 lines
5.7 KiB
Plaintext
<!-- doc/src/sgml/ref/create_foreign_table.sgml -->
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<refentry id="SQL-CREATEFOREIGNTABLE">
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<refmeta>
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<refentrytitle>CREATE FOREIGN TABLE</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>CREATE FOREIGN TABLE</refname>
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<refpurpose>define a new foreign table</refpurpose>
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</refnamediv>
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<indexterm zone="sql-createforeigntable">
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<primary>CREATE FOREIGN TABLE</primary>
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</indexterm>
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<refsynopsisdiv>
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<synopsis>
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CREATE FOREIGN TABLE [ IF NOT EXISTS ] <replaceable class="PARAMETER">table_name</replaceable> ( [
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{ <replaceable class="PARAMETER">column_name</replaceable> <replaceable class="PARAMETER">data_type</replaceable> [ NULL | NOT NULL ] }
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[, ... ]
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] )
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SERVER <replaceable class="parameter">server_name</replaceable>
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[ OPTIONS ( <replaceable class="PARAMETER">option</replaceable> '<replaceable class="PARAMETER">value</replaceable>' [, ... ] ) ]
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</synopsis>
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</refsynopsisdiv>
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<refsect1 id="SQL-CREATEFOREIGNTABLE-description">
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<title>Description</title>
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<para>
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<command>CREATE FOREIGN TABLE</command> will create a new foreign table
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in the current database. The table will be owned by the user issuing the
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command.
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</para>
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<para>
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If a schema name is given (for example, <literal>CREATE FOREIGN TABLE
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myschema.mytable ...</>) then the table is created in the specified
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schema. Otherwise it is created in the current schema.
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The name of the foreign table must be
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distinct from the name of any other foreign table, table, sequence, index,
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or view in the same schema.
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</para>
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<para>
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<command>CREATE FOREIGN TABLE</command> also automatically creates a data
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type that represents the composite type corresponding to one row of
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the foreign table. Therefore, foreign tables cannot have the same
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name as any existing data type in the same schema.
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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 NOT EXISTS</></term>
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<listitem>
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<para>
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Do not throw an error if a relation with the same name already exists.
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A notice is issued in this case. Note that there is no guarantee that
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the existing relation is anything like the one that would have been
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created.
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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">table_name</replaceable></term>
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<listitem>
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<para>
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The name (optionally schema-qualified) of the table to be created.
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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">column_name</replaceable></term>
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<listitem>
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<para>
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The name of a column to be created in the new table.
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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">data_type</replaceable></term>
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<listitem>
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<para>
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The data type of the column. This can include array
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specifiers. For more information on the data types supported by
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<productname>PostgreSQL</productname>, refer to <xref
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linkend="datatype">.
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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>NOT NULL</></term>
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<listitem>
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<para>
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The column is not allowed to contain null values.
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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>NULL</></term>
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<listitem>
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<para>
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The column is allowed to contain null values. This is the default.
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</para>
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<para>
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This clause is only provided for compatibility with
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non-standard SQL databases. Its use is discouraged in new
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applications.
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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">server_name</replaceable></term>
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<listitem>
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<para>
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The name of an existing server for the foreign table.
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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>OPTIONS ( <replaceable class="PARAMETER">option</replaceable> '<replaceable class="PARAMETER">value</replaceable>' [, ...] )</literal></term>
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<listitem>
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<para>
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Options to be associated with the new foreign table.
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The allowed option names and values are specific to each foreign
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data wrapper and are validated using the foreign-data wrapper's
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validator function. Option names must be unique.
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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-CREATEFOREIGNTABLE-examples">
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<title>Examples</title>
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<para>
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Create foreign table <structname>films</> with <structname>film_server</>:
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<programlisting>
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CREATE FOREIGN TABLE films (
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code char(5) NOT NULL,
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title varchar(40) NOT NULL,
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did integer NOT NULL,
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date_prod date,
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kind varchar(10),
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len interval hour to minute
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)
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SERVER film_server;
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</programlisting>
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</para>
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</refsect1>
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<refsect1 id="SQL-CREATEFOREIGNTABLE-compatibility">
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<title id="SQL-CREATEFOREIGNTABLE-compatibility-title">Compatibility</title>
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<para>
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The <command>CREATE FOREIGN TABLE</command> command largely conforms to the
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<acronym>SQL</acronym> standard; however, much as with
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<link linkend="sql-createtable"><command>CREATE TABLE</></link>,
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<literal>NULL</> constraints and zero-column foreign tables are permitted.
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</para>
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</refsect1>
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<refsect1>
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<title>See Also</title>
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<simplelist type="inline">
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<member><xref linkend="sql-alterforeigntable"></member>
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<member><xref linkend="sql-dropforeigntable"></member>
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<member><xref linkend="sql-createtable"></member>
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<member><xref linkend="sql-createserver"></member>
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</simplelist>
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</refsect1>
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</refentry>
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