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><H1
><A
NAME="SQL-CREATETABLEAS"
></A
>CREATE TABLE AS</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN71251"
></A
><H2
>Name</H2
>CREATE TABLE AS -- define a new table from the results of a query</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN71256"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE <TT
CLASS="REPLACEABLE"
><I
>table_name</I
></TT
>
[ (<TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> [, ...] ) ]
[ WITH ( <TT
CLASS="REPLACEABLE"
><I
>storage_parameter</I
></TT
> [= <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>] [, ... ] ) | WITH OIDS | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE <TT
CLASS="REPLACEABLE"
><I
>tablespace_name</I
></TT
> ]
AS <TT
CLASS="REPLACEABLE"
><I
>query</I
></TT
>
[ WITH [ NO ] DATA ]</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71264"
></A
><H2
>Description</H2
><P
> <TT
CLASS="COMMAND"
>CREATE TABLE AS</TT
> creates a table and fills it
with data computed by a <TT
CLASS="COMMAND"
>SELECT</TT
> command.
The table columns have the
names and data types associated with the output columns of the
<TT
CLASS="COMMAND"
>SELECT</TT
> (except that you can override the column
names by giving an explicit list of new column names).
</P
><P
> <TT
CLASS="COMMAND"
>CREATE TABLE AS</TT
> bears some resemblance to
creating a view, but it is really quite different: it creates a new
table and evaluates the query just once to fill the new table
initially. The new table will not track subsequent changes to the
source tables of the query. In contrast, a view re-evaluates its
defining <TT
CLASS="COMMAND"
>SELECT</TT
> statement whenever it is
queried.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71273"
></A
><H2
>Parameters</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>GLOBAL</TT
> or <TT
CLASS="LITERAL"
>LOCAL</TT
></DT
><DD
><P
> Ignored for compatibility. Use of these keywords is deprecated;
refer to <A
HREF="sql-createtable.html"
>CREATE TABLE</A
> for details.
</P
></DD
></DL
></DIV
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>TEMPORARY</TT
> or <TT
CLASS="LITERAL"
>TEMP</TT
></DT
><DD
><P
> If specified, the table is created as a temporary table.
Refer to <A
HREF="sql-createtable.html"
>CREATE TABLE</A
> for details.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>UNLOGGED</TT
></DT
><DD
><P
> If specified, the table is created as an unlogged table.
Refer to <A
HREF="sql-createtable.html"
>CREATE TABLE</A
> for details.
</P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>table_name</I
></TT
></DT
><DD
><P
> The name (optionally schema-qualified) of the table to be created.
</P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
></DT
><DD
><P
> The name of a column in the new table. If column names are not
provided, they are taken from the output column names of the query.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>WITH ( <TT
CLASS="REPLACEABLE"
><I
>storage_parameter</I
></TT
> [= <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>] [, ... ] )</TT
></DT
><DD
><P
> This clause specifies optional storage parameters for the new table;
see <A
HREF="sql-createtable.html#SQL-CREATETABLE-STORAGE-PARAMETERS"
><I
>Storage Parameters</I
></A
> for more
information. The <TT
CLASS="LITERAL"
>WITH</TT
> clause
can also include <TT
CLASS="LITERAL"
>OIDS=TRUE</TT
> (or just <TT
CLASS="LITERAL"
>OIDS</TT
>)
to specify that rows of the new table
should have OIDs (object identifiers) assigned to them, or
<TT
CLASS="LITERAL"
>OIDS=FALSE</TT
> to specify that the rows should not have OIDs.
See <A
HREF="sql-createtable.html"
>CREATE TABLE</A
> for more information.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>WITH OIDS</TT
><BR><TT
CLASS="LITERAL"
>WITHOUT OIDS</TT
></DT
><DD
><P
> These are obsolescent syntaxes equivalent to <TT
CLASS="LITERAL"
>WITH (OIDS)</TT
>
and <TT
CLASS="LITERAL"
>WITH (OIDS=FALSE)</TT
>, respectively. If you wish to give
both an <TT
CLASS="LITERAL"
>OIDS</TT
> setting and storage parameters, you must use
the <TT
CLASS="LITERAL"
>WITH ( ... )</TT
> syntax; see above.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>ON COMMIT</TT
></DT
><DD
><P
> The behavior of temporary tables at the end of a transaction
block can be controlled using <TT
CLASS="LITERAL"
>ON COMMIT</TT
>.
The three options are:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>PRESERVE ROWS</TT
></DT
><DD
><P
> No special action is taken at the ends of transactions.
This is the default behavior.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>DELETE ROWS</TT
></DT
><DD
><P
> All rows in the temporary table will be deleted at the end
of each transaction block. Essentially, an automatic <A
HREF="sql-truncate.html"
>TRUNCATE</A
> is done
at each commit.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>DROP</TT
></DT
><DD
><P
> The temporary table will be dropped at the end of the current
transaction block.
</P
></DD
></DL
></DIV
><P></P
></DD
><DT
><TT
CLASS="LITERAL"
>TABLESPACE <TT
CLASS="REPLACEABLE"
><I
>tablespace_name</I
></TT
></TT
></DT
><DD
><P
> The <TT
CLASS="REPLACEABLE"
><I
>tablespace_name</I
></TT
> is the name
of the tablespace in which the new table is to be created.
If not specified,
<A
HREF="runtime-config-client.html#GUC-DEFAULT-TABLESPACE"
>default_tablespace</A
> is consulted, or
<A
HREF="runtime-config-client.html#GUC-TEMP-TABLESPACES"
>temp_tablespaces</A
> if the table is temporary.
</P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>query</I
></TT
></DT
><DD
><P
> A <A
HREF="sql-select.html"
>SELECT</A
>, <A
HREF="sql-select.html#SQL-TABLE"
>TABLE</A
>, or <A
HREF="sql-values.html"
>VALUES</A
>
command, or an <A
HREF="sql-execute.html"
>EXECUTE</A
> command that runs a
prepared <TT
CLASS="COMMAND"
>SELECT</TT
>, <TT
CLASS="COMMAND"
>TABLE</TT
>, or
<TT
CLASS="COMMAND"
>VALUES</TT
> query.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>WITH [ NO ] DATA</TT
></DT
><DD
><P
> This clause specifies whether or not the data produced by the query
should be copied into the new table. If not, only the table structure
is copied. The default is to copy the data.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71380"
></A
><H2
>Notes</H2
><P
> This command is functionally similar to <A
HREF="sql-selectinto.html"
>SELECT INTO</A
>, but it is
preferred since it is less likely to be confused with other uses of
the <TT
CLASS="COMMAND"
>SELECT INTO</TT
> syntax. Furthermore, <TT
CLASS="COMMAND"
>CREATE
TABLE AS</TT
> offers a superset of the functionality offered
by <TT
CLASS="COMMAND"
>SELECT INTO</TT
>.
</P
><P
> Prior to <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 8.0, <TT
CLASS="COMMAND"
>CREATE
TABLE AS</TT
> always included OIDs in the table it
created. As of <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 8.0,
the <TT
CLASS="COMMAND"
>CREATE TABLE AS</TT
> command allows the user to
explicitly specify whether OIDs should be included. If the
presence of OIDs is not explicitly specified,
the <A
HREF="runtime-config-compatible.html#GUC-DEFAULT-WITH-OIDS"
>default_with_oids</A
> configuration variable is
used. As of <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 8.1,
this variable is false by default, so the default behavior is not
identical to pre-8.0 releases. Applications that
require OIDs in the table created by <TT
CLASS="COMMAND"
>CREATE TABLE
AS</TT
> should explicitly specify <TT
CLASS="LITERAL"
>WITH (OIDS)</TT
>
to ensure desired behavior.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71396"
></A
><H2
>Examples</H2
><P
> Create a new table <TT
CLASS="LITERAL"
>films_recent</TT
> consisting of only
recent entries from the table <TT
CLASS="LITERAL"
>films</TT
>:
</P><PRE
CLASS="PROGRAMLISTING"
>CREATE TABLE films_recent AS
SELECT * FROM films WHERE date_prod >= '2002-01-01';</PRE
><P>
</P
><P
> To copy a table completely, the short form using
the <TT
CLASS="LITERAL"
>TABLE</TT
> command can also be used:
</P><PRE
CLASS="PROGRAMLISTING"
>CREATE TABLE films2 AS
TABLE films;</PRE
><P>
</P
><P
> Create a new temporary table <TT
CLASS="LITERAL"
>films_recent</TT
>, consisting of
only recent entries from the table <TT
CLASS="LITERAL"
>films</TT
>, using a
prepared statement. The new table has OIDs and will be dropped at commit:
</P><PRE
CLASS="PROGRAMLISTING"
>PREPARE recentfilms(date) AS
SELECT * FROM films WHERE date_prod > $1;
CREATE TEMP TABLE films_recent WITH (OIDS) ON COMMIT DROP AS
EXECUTE recentfilms('2002-01-01');</PRE
><P></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71409"
></A
><H2
>Compatibility</H2
><P
> <TT
CLASS="COMMAND"
>CREATE TABLE AS</TT
> conforms to the <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
standard. The following are nonstandard extensions:
<P
></P
></P><UL
COMPACT="COMPACT"
><LI
><P
> The standard requires parentheses around the subquery clause; in
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>, these parentheses are
optional.
</P
></LI
><LI
><P
> In the standard, the <TT
CLASS="LITERAL"
>WITH [ NO ] DATA</TT
> clause
is required; in PostgreSQL it is optional.
</P
></LI
><LI
><P
><SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> handles temporary tables in a way
rather different from the standard; see
<A
HREF="sql-createtable.html"
>CREATE TABLE</A
>
for details.
</P
></LI
><LI
><P
> The <TT
CLASS="LITERAL"
>WITH</TT
> clause is a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
extension; neither storage parameters nor OIDs are in the standard.
</P
></LI
><LI
><P
> The <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> concept of tablespaces is not
part of the standard. Hence, the clause <TT
CLASS="LITERAL"
>TABLESPACE</TT
>
is an extension.
</P
></LI
></UL
><P></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN71433"
></A
><H2
>See Also</H2
><A
HREF="sql-createtable.html"
>CREATE TABLE</A
>, <A
HREF="sql-execute.html"
>EXECUTE</A
>, <A
HREF="sql-select.html"
>SELECT</A
>, <A
HREF="sql-selectinto.html"
>SELECT INTO</A
>, <A
HREF="sql-values.html"
>VALUES</A
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