Explain the significance of OR REPLACE, FORCE and NOFORCE while creating view.
The syntax for creating a view is:
CREATE [OR REPLACE] [FORCE|NOFORCE] VIEW view_name [alias[, alias]…)]
AS subquery
[WITH CHECK OPTION [CONSTRAINT constraint] ]
[WITH READ ONLY]
Subquery is SELECT statement (cannot contain the ORDER BY clause).
OR REPLACE is used to re-create the view if it already exists without having to drop it first.
FORCE creates the view regardless of whether or not the base table(s) exist.
NOFORCE creates the view only if the base tables exist.
