CREATE TABLE ASCREATE TABLE AS7SQL - Language StatementsCREATE TABLE ASdefine a new table from the results of a query
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name
[ (column_name [, ...] ) ]
[ USING method ]
[ WITH ( storage_parameter [= value] [, ... ] ) | WITHOUT OIDS ]
[ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
[ TABLESPACE tablespace_name ]
AS query
[ WITH [ NO ] DATA ]
DescriptionCREATE TABLE AS creates a table and fills it
with data computed by a SELECT command.
The table columns have the
names and data types associated with the output columns of the
SELECT (except that you can override the column
names by giving an explicit list of new column names).
CREATE TABLE AS 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 SELECT statement whenever it is
queried.
CREATE TABLE AS requires CREATE
privilege on the schema used for the table.
ParametersGLOBAL or LOCAL
Ignored for compatibility. Use of these keywords is deprecated;
refer to for details.
TEMPORARY or TEMP
If specified, the table is created as a temporary table.
Refer to for details.
UNLOGGED
If specified, the table is created as an unlogged table.
Refer to for details.
IF NOT EXISTS
Do not throw an error if a relation with the same name already
exists; simply issue a notice and leave the table unmodified.
table_name
The name (optionally schema-qualified) of the table to be created.
column_name
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.
USING method
This optional clause specifies the table access method to use to store
the contents for the new table; the method needs be an access method of
type TABLE. See for more
information. If this option is not specified, the default table access
method is chosen for the new table. See for more information.
WITH ( storage_parameter [= value] [, ... ] )
This clause specifies optional storage parameters for the new table;
see in the
documentation for more
information. For backward-compatibility the WITH
clause for a table can also include OIDS=FALSE to
specify that rows of the new table should contain no OIDs (object
identifiers), OIDS=TRUE is not supported anymore.
WITHOUT OIDS
This is backward-compatible syntax for declaring a table
WITHOUT OIDS, creating a table WITH
OIDS is not supported anymore.
ON COMMIT
The behavior of temporary tables at the end of a transaction
block can be controlled using ON COMMIT.
The three options are:
PRESERVE ROWS
No special action is taken at the ends of transactions.
This is the default behavior.
DELETE ROWS
All rows in the temporary table will be deleted at the end
of each transaction block. Essentially, an automatic TRUNCATE is done
at each commit.
DROP
The temporary table will be dropped at the end of the current
transaction block.
TABLESPACE tablespace_name
The tablespace_name is the name
of the tablespace in which the new table is to be created.
If not specified,
is consulted, or
if the table is temporary.
query
A SELECT, TABLE, or VALUES
command, or an EXECUTE command that runs a
prepared SELECT, TABLE, or
VALUES query.
WITH [ NO ] DATA
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.
Notes
This command is functionally similar to , but it is
preferred since it is less likely to be confused with other uses of
the SELECT INTO syntax. Furthermore, CREATE
TABLE AS offers a superset of the functionality offered
by SELECT INTO.
Examples
Create a new table films_recent consisting of only
recent entries from the table films:
CREATE TABLE films_recent AS
SELECT * FROM films WHERE date_prod >= '2002-01-01';
To copy a table completely, the short form using
the TABLE command can also be used:
CREATE TABLE films2 AS
TABLE films;
Create a new temporary table films_recent, consisting of
only recent entries from the table films, using a
prepared statement. The new table will be dropped at commit:
PREPARE recentfilms(date) AS
SELECT * FROM films WHERE date_prod > $1;
CREATE TEMP TABLE films_recent ON COMMIT DROP AS
EXECUTE recentfilms('2002-01-01');
CompatibilityCREATE TABLE AS conforms to the SQL
standard. The following are nonstandard extensions:
The standard requires parentheses around the subquery clause; in
PostgreSQL, these parentheses are
optional.
In the standard, the WITH [ NO ] DATA clause
is required; in PostgreSQL it is optional.
PostgreSQL handles temporary tables in a way
rather different from the standard; see
for details.
The WITH clause is a PostgreSQL
extension; storage parameters are not in the standard.
The PostgreSQL concept of tablespaces is not
part of the standard. Hence, the clause TABLESPACE
is an extension.
See Also