Re: Unique Keys

The syntax for that predicate in SQL-92 is:

(S1, T1) OVERLAPS (S2, T2)
and it is defined as:

(S1 > S2 AND NOT (S1 >= T2 AND T1 >= T2))
 OR (S2 > S1 AND NOT (S2 >= T1 AND T2 >= T1))  OR (S1 = S2 AND (T1 <> T2 OR T1 = T2))

Rick Snodgrass introduced this into the standards. Received on Sat Nov 27 2004 - 17:55:25 CST