How to alter column size of a view in Oracle

Question

I am trying to alter the column size of a view with the same command that we use for table like :

alter table 
STUDENT
modify (
    ROLL_NO VARCHAR2(80)
);
         


        

Answer 1

A view is simply saved query and "inherits" column type from underlying base table. So if you need to change metadata you should alter view definition:

ALTER VIEW view_students
AS
SELECT CAST(roll_no AS VARCHAR2(80)) AS roll_no,
     ...
FROM tab_students;

If you want to change data type to store longer strings, then you need to locate base table and alter it instead:

ALTER VIEW tab_students
MODIFY (ROLL_NO VARCHAR2(80));