CREATE VIEW() SQL Commands CREATE VIEW()NAME
CREATE VIEW - Constructs a virtual table
SYNOPSIS
CREATE VIEW view AS SELECT query
INPUTS
view The name of a view to be created.
query An SQL query which will provide the columns and rows of the
view.
Refer to the SELECT statement for more information about valid
arguments.
OUTPUTS
CREATE The message returned if the view is successfully created.
ERROR: Relation 'view' already exists
This error occurs if the view specified already exists in the
database.
NOTICE create: attribute named "column" has an unknown type
The view will be created having a column with an unknown type if
you do not specify it. For example, the following command gives
a warning:
CREATE VIEW vista AS SELECT 'Hello World'
whereas this command does not:
CREATE VIEW vista AS SELECT text 'Hello World'
DESCRIPTION
CREATE VIEW will define a view of a table. This view is not physically
materialized. Specifically, a query rewrite retrieve rule is automati‐
cally generated to support retrieve operations on views.
NOTES
Currently, views are read only.
Use the DROP VIEW statement to drop views.
USAGE
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
(2 rows)
COMPATIBILITY
SQL92
SQL92 specifies some additional capabilities for the CREATE VIEW state‐
ment:
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:
CHECK OPTION
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.
LOCAL Check for integrity on this view.
CASCADE
Check for integrity on this view and on any dependent view. CAS‐
CADE is assumed if neither CASCADE nor LOCAL is specified.
SQL - Language Statements 29 March 2001 CREATE VIEW()
