CREATE VIEW view
AS SELECT query
The name of a view to be created.
An SQL query which will provide the columns and rows of the view.
Refer to the SELECT statement for more information about valid arguments.
The message returned if the view is successfully created.
This error occurs if the view specified already exists in the database.
The view will be created having a column with an unknown type if you do not specify it. For example, the following command gives an error:
CREATE VIEW vista AS SELECT 'Hello World'
whereas this command does not:
CREATE VIEW vista AS SELECT 'Hello World'::text
CREATE VIEW will define a view of a table. This view is not physically materialized. Specifically, a query rewrite retrieve rule is automatically generated to support retrieve operations on views.
Use the DROP VIEW statement to drop views.
Currently, views are read only.
Create a view consisting of all Comedy films:
CREATE VIEW kinds AS
SELECT *
FROM films
WHERE kind = 'Comedy';
SELECT * FROM kinds;
code |title |did| date_prod|kind |len
-----+-------------------------+---+----------+----------+------
UA502|Bananas |105|1971-07-13|Comedy | 01:22
C_701|There's a Girl in my Soup|107|1970-06-11|Comedy | 01:36
SQL92 specifies some additional capabilities for the CREATE VIEW statement:
CREATE VIEW view [ column [, ...] ]
AS SELECT expression [ AS colname ] [, ...]
FROM table [ WHERE condition ]
[ WITH [ CASCADE | LOCAL ] CHECK OPTION ]
The optional clauses for the full SQL92 command are:
This option is to do with updatable views. All INSERTs and UPDATEs on the view will be checked to ensure data satisfy the view-defining condition. If they do not, the update will be rejected.
Check for integrity on this view.
Check for integrity on this view and on any dependent view. CASCADE is assumed if neither CASCADE nor LOCAL is specified.