CREATE VIEW¶
Synopsis¶
CREATE [ OR REPLACE ] VIEW view_name
[ SECURITY { DEFINER | INVOKER } ]
AS query
Description¶
Create a new view of a SELECT query. The view is a logical table that can be referenced by future queries. Views do not contain any data. Instead, the query stored by the view is executed every time the view is referenced by another query.
The optional OR REPLACE clause causes the view to be replaced if it
already exists rather than raising an error.
Security¶
In the default DEFINER security mode, tables referenced in the view
are accessed using the permissions of the view owner (the creator or
definer of the view) rather than the user executing the query. This
allows providing restricted access to the underlying tables, for which
the query user may not be allowed to access directly. Note that the
current_user function will return the query user, not the view owner,
and thus may be used to filter out rows or otherwise restrict access
based on the user currently accessing the view.
In the INVOKER security mode, tables referenced in the view are
accessed using the permissions of the query user (the invoker of the
view). A view created in this mode is simply a stored query.
The default-view-security-mode can be used to configure the default
security mode for view creation.
Examples¶
Create a simple view test over the orders table:
CREATE VIEW test AS
SELECT orderkey, orderstatus, totalprice / 2 AS half
FROM orders
Create a view orders_by_date that summarizes orders:
CREATE VIEW orders_by_date AS
SELECT orderdate, sum(totalprice) AS price
FROM orders
GROUP BY orderdate
Create a view that replaces an existing view:
CREATE OR REPLACE VIEW test AS
SELECT orderkey, orderstatus, totalprice / 4 AS quarter
FROM orders
Set the default view security mode to INVOKER:
SET SESSION default_view_security_mode='INVOKER'