Bug #33200 Implement of Except
Submitted: 13 Dec 2007 7:04 Modified: 3 Jan 2008 15:37
Reporter: Axel Bayerl Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Server Severity:S4 (Feature request)
Version:5.0.45 OS:Linux (except statement)
Assigned to: CPU Architecture:Any
Tags: except, feature, statement

[13 Dec 2007 7:04] Axel Bayerl 
Description:
I wold be very happy if you implement the EXCEPT keyword on MySQL. Because i need its functionality but i don't know how to do it here (only on SQL).
Thanks for your attention.

How to repeat:
-
[13 Dec 2007 11:53] Susanne Ebrecht 
Please, would you let us know, what EXCEPT should do, especially?
[13 Dec 2007 20:09] Axel Bayerl 
Hello Susanne. I have 3 tables: member, stage and score. I want to know which member has not been scored.

On SQLITE3 i make

(select memberid, stageid from member, stage)
EXCEPT
(select memberid, stageid from score)

It is (select memberid, stageid from member, stage) makes an cartesian combination between table member and table stage. And with (select memberid, stageid from score) i obtain the scores i actualy have on the table.
The except gives me the rows of the first select does are not in the secon select.

The SQLITE3 docs says: "EXCEPT takes the result of left SELECT after removing the results of the right SELECT"

PS: With EXCEPT you can also implement INTERSECT: "The INTERSECT operator takes the intersection of the results of the left and right SELECTs"
[14 Dec 2007 12:41] Susanne Ebrecht 
Many thanks for choosing MySQL and for writing a feature request.
[3 Jan 2008 15:37] Susanne Ebrecht 
This is a duplicate of bug #1309