How to add ID autogenerate column to VIEW

Question

Hi all,
Could anybody help me create a View with its own identifier column?
I use to create VIEW following syntax:
CREATE VIEW MY_VIEW AS
t1.f1 FIELD_1, t2.f2 FIELD_2
FROM t1 LEFT JOIN t2 ON t1.f3 = t2.f3
I tried to use sequence like:
CREATE VIEW QUALIFIED_CHAR_REL AS
SEQ.nextval ID,
t1.f1 FIELD_1, t2.f2 FIELD_2
FROM DUAL, t1 LEFT JOIN t2 ON t1.f3 = t2.f3
or
CREATE VIEW QUALIFIED_CHAR_REL AS
SELECT (SEQ.nextval FROM DUAL) ID,
t1.f1 FIELD_1, t2.f2 FIELD_2
FROM t1 LEFT JOIN t2 ON t1.f3 = t2.f3
No result. Is it at all possible? What solutions could match this situation?
Thx in advance for help!
Edited by: 878800 on Aug 11, 2011 3:25 AM

Answer 1

Could anybody help me create a View with its own identifier column?Why would you want to do this? A view is simply "View" of data in other tables. Any ID you would artificially create in your view for this data is not persistent. More over, as a view executes the underlying query each time someone selects from the view, your artificial ID would be constantly changing (if you were to use a Sequence, as you attempted).
Once the data in your underlying table(s) changed to the point where the View's SQL excluded a record you would loose the ID and data from your view. Any table data that is using this view ID would instantly become orphaned and invalid. Creating a view with it's own ID is a bad idea in my opinion and is prone to cause errors in any other table or view that might use this view ID. It would be better to display the Primary Key ID of the primary table used in your view than to create an artifical ID just for your view.
Also, as your question does not pertain to Oracle Forms, it would be best if you had posted your question in the PL/SQL forum.
Craig...
Edited by: CraigB on Aug 11, 2011 9:04 AM