Bug #31336 | provide intersect and except, not only union | ||
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Submitted: | 2 Oct 2007 10:29 | Modified: | 21 Oct 2022 12:30 |
Reporter: | Maciej Pilichowski | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: DML | Severity: | S4 (Feature request) |
Version: | 5.0.45 | OS: | Linux |
Assigned to: | CPU Architecture: | Any |
[2 Oct 2007 10:29]
Maciej Pilichowski
[3 Oct 2007 12:03]
Valeriy Kravchuk
Thank you for a reasonable feature request.
[7 Apr 2009 15:53]
luc hoegaerts
You are right, intersect and except are necessary features that the developers MUST implement again. The reason the theoreticians of Mysql don't implement it, is simple: the intersection and except statements are not elementary, because they can be composed with other commands. Yes, from a theoretical perspective they are absolutely right. But they forget the real world practicality of these commands. In dynamic sql query building, one does not know in advance the names of tables, or column names (only their type), and one can intersect/difference the results only in a sequential manner. Intersect and except nicely fit this task. Bypassing these commands makes writing dynamic SQL very very difficult. (not impossible, but it requires suboptimal queries and more coding) By the way, intersect and except are very easy to implment and run very fast. Developers, please bring this issue to a higher level! Remark it is not a 'wish', but it is a 'must have'. best regards, luc hoegaerts
[20 Oct 2022 20:47]
Frederic Descamps
finally there ! See https://lefred.be/content/intersect-and-except-in-mysql-8-0/
[21 Oct 2022 12:30]
Jon Stephens
Fixed in MySQL 8.0.31 by WL#349. Closed.