Hi Wendy, hmm......
I think I understand. You could READU the PERSON file with just the datafield as the ID to 'lock' that UserID, then proceed with the rest of the logic as is. You don't even need to WRITE the UserID as a record to the PERSON file, just use it as a precursor to the rest of your logic which I assume has a field*field locking scheme already in place. This way if another user tried the UserID a millisecond after the first user, you could send a 'please wait' message, until the UserID was RELEASE'd by the first process. Then use an index to tell the second guy he was out of luck and to try another user name. Sounds like it should work........ hth! Allen E. Elwood Senior Programmer Analyst Sysmark Information Systems, Inc. Direct (818) 361-5251 Fax (818) 361-5251 Cell (818) 359-8162 Home (818) 361-7217 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Wendy Smoak Sent: Friday, October 08, 2004 13:12 To: [EMAIL PROTECTED] Subject: RE: [U2] Enforcing uniqueness of two fields per record? > Richard A. Wilson wrote: > cant you just index both fields and use your check index logic That's what I do now, but there's no guarantee of uniqueness. The key is guaranteed unique-- you just can't write two records with the same key. But AFAIK nothing is going to stop me writing two records with a data field set to the same value. I think I have concurrency issues-- if two users try for the same UserID at the same time, they could both "think" they've got it. (Same code running twice, one just after the other.) That's why I'm thinking to use a database trigger to move that final check as close to the write as possible. -- Wendy Smoak ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/
