Pretty nifty Larry. Really shows how powerful SQL is. -- Dennis McGrath mailto:[EMAIL PROTECTED]
-- Productivity Tools for R:Base Programmers http://www.enteract.com/~mcgrath/dennis -- Full time consultant with: SQL Resources Group Steve Hartmann Oak Park, IL mailto:[EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Lawrence Lustig Sent: Tuesday, October 23, 2001 9:25 PM To: [EMAIL PROTECTED] Subject: Re: SQL Impossibility? Sorry for the premature send on the previous response. > Is there an SQL way to return the empty slots: > 13:00 13:30 > 14:30 15:00 SELECT End, MIN(t3.Start) + FROM YourTable t1, YourTable t3 + WHERE NOT EXISTS + (SELECT * FROM YourTable t2 WHERE t2.Start = t1.End) + AND t3.Start > t1.End + GROUP BY End Translated into "English Query Language" this says: Select all the End times that are not also in the table as a Start time (the NOT EXISTS part) and also give me the minimum Start time that is greater than the selected End time. The period from the "unstarted" end to the next highest start time is a hole in the schedule. -- Larry _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com
