CREATE TABLE AS
Section: PostgreSQL 15.6 Documentation (7)
Updated: 2024
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NAME
CREATE_TABLE_AS - define a new table from the results of a query
SYNOPSIS
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 ]
DESCRIPTION
CREATE 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.
PARAMETERS
GLOBAL or LOCAL
-
Ignored for compatibility. Use of these keywords is deprecated; refer to
CREATE TABLE (CREATE_TABLE(7))
for details.
TEMPORARY or TEMP
-
If specified, the table is created as a temporary table. Refer to
CREATE TABLE (CREATE_TABLE(7))
for details.
UNLOGGED
-
If specified, the table is created as an unlogged table. Refer to
CREATE TABLE (CREATE_TABLE(7))
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
Chapter 63
for more information. If this option is not specified, the default table access method is chosen for the new table. See
default_table_access_method
for more information.
WITH ( storage_parameter [= value] [, ... ] )
-
This clause specifies optional storage parameters for the new table; see
Storage Parameters
in the
CREATE TABLE (CREATE_TABLE(7))
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,
default_tablespace
is consulted, or
temp_tablespaces
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
SELECT INTO (SELECT_INTO(7)), 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');
COMPATIBILITY
CREATE 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
CREATE TABLE (CREATE_TABLE(7))
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
CREATE MATERIALIZED VIEW (CREATE_MATERIALIZED_VIEW(7)), CREATE TABLE (CREATE_TABLE(7)), EXECUTE(7), SELECT(7), SELECT INTO (SELECT_INTO(7)), VALUES(7)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- PARAMETERS
-
- NOTES
-
- EXAMPLES
-
- COMPATIBILITY
-
- SEE ALSO
-
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