Check constraint for start/end date

Question

I have a table with a 'start_date' attribute and an 'end_date' attribute. I want to create a check constraint in Oracle that prevents the end_date from preceding the start_date and the start_date from exceeding the end_date. Anybody help me out?

Answer 1

Add a CHECK constraint :

ALTER TABLE tableX
  ADD CONSTRAINT end_date_later_than_start_date_CK   -- a sensible name 
                                                     -- for the constraint
    CHECK (start_date <= end_date) 
    <optional constraint state>
; 

The optional constraint states are described in the link. For example, you can specify ENABLE NOVALIDATE , if you want to enable the constraint for future insertions (and updates) but not check existing rows.

Answer 2

I'm not an Oracle person but I found this on the web and it may helps. Take the timespan for these two dates. Here is a link for documentation :

INTERVAL Expressions