CREATE TABLE AS
CREATE TABLE AS
CREATE TABLE AS — define a new table from the results of a query
Synopsis
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
orLOCAL
Ignored for compatibility. Use of these keywords is deprecated; refer to CREATE TABLE for details.
TEMPORARY
orTEMP
If specified, the table is created as a temporary table. Refer to CREATE TABLE for details.
UNLOGGED
If specified, the table is created as an unlogged table. Refer to CREATE TABLE for details.
IF NOT EXISTS
Do not throw an error if a relation with the same name already exists. A notice is issued in this case. Refer to CREATE TABLE for details.
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
. If this option is not specified, the default table access method is chosen for the new table.WITH ( `storage_parameter` [= `value`] [, ... ] )
This clause specifies optional storage parameters for the new table; see Storage Parameters in the CREATE TABLE documentation for more information. For backward-compatibility the
WITH
clause for a table can also includeOIDS=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 tableWITH 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 option is:PRESERVE ROWS
No special action is taken at the ends of transactions. This is the default behavior.
query
A SELECT, TABLE, or VALUES command, or an EXECUTE command that runs a prepared
SELECT
,TABLE
, orVALUES
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, 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
:
To copy a table completely, the short form using the TABLE
command can also be used:
Create a new temporary table films_recent
, consisting of only recent entries from the table films
, using a prepared statement:
Compatibility
CREATE TABLE AS
conforms to the SQL standard. The following are nonstandard extensions:
-
The standard requires parentheses around the subquery clause; in Tacnode, these parentheses are optional.
-
In the standard, the
WITH [ NO ] DATA
clause is required; in PostgreSQL it is optional. -
Tacnode handles temporary tables in a way rather different from the standard; see CREATE TABLE for details.
-
The
WITH
clause is a Tacnode extension; storage parameters are not in the standard.