CREATE TABLE AS

Function

CREATE TABLE AS creates a table based on the results of a query.

It creates a table and fills it with data obtained using SELECT. The table columns have the names and data types associated with the output columns of SELECT (except that you can override the SELECT output column names by giving an explicit list of new column names).

CREATE TABLE AS queries a source table once and writes the data in a new table. The result in the query view changes with the source table. In contrast, the view re-computes and defines its SELECT statement at each query.

Precautions

This section describes only the new syntax of Dolphin. The original syntax of MogDB is not deleted or modified.

Syntax

CREATE [ [ GLOBAL | LOCAL ] [ TEMPORARY | TEMP ] | UNLOGGED ] TABLE table_name
    [ (column_name [, ...] ) ]
    [ WITH ( {storage_parameter = value} [, ... ] ) ]
    [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ]
    [ COMPRESS | NOCOMPRESS ]
    [ TABLESPACE tablespace_name ]
    [ AS ] query
    [ WITH [ NO ] DATA ];

Parameter Description

[ AS ] query

Specifies a SELECT or VALUES command, or an EXECUTE command that runs a prepared SELECT, or VALUES query.

The AS keyword is optional. However, if the query contains the WITH statement, you must use parentheses to enclose the query. The following is an example:
```
CREATE TABLE t_new (WITH temp_t(a, b) AS (SELECT a, b FROM t_old) SELECT * FROM temp_t);
```

Examples

--Create the tpcds.store_returns table.
MogDB=# CREATE TABLE tpcds.store_returns
(
    W_WAREHOUSE_SK            INTEGER               NOT NULL,
    W_WAREHOUSE_ID            CHAR(16)              NOT NULL,
    sr_item_sk                VARCHAR(20)                   ,
    W_WAREHOUSE_SQ_FT         INTEGER                       
);
--Create the tpcds.store_returns_t1 table and insert numbers that are greater than 16 in the sr_item_sk column of the tpcds.store_returns table:
MogDB=# CREATE TABLE tpcds.store_returns_t1 AS SELECT * FROM tpcds.store_returns WHERE sr_item_sk > '4795';

--Copy tpcds.store_returns to create the tpcds.store_returns_t2 table.
MogDB=# CREATE TABLE tpcds.store_returns_t2 AS table tpcds.store_returns;

--Delete a table.
MogDB=# DROP TABLE tpcds.store_returns_t1 ;
MogDB=# DROP TABLE tpcds.store_returns_t2 ;
MogDB=# DROP TABLE tpcds.store_returns;

Helpful Links

CREATE TABLE，SELECT