[Django] #24609: Concat on MySQL doesn't need the coalesce step
Django
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Reporter: adamchainz | Owner: nobody
Type: Cleanup/optimization | Status: new
Component: Database layer (models, ORM) | Version: 1.8
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 1
Easy pickings: 0 | UI/UX: 0
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The new Concat database function calls ConcatPair which does a coalesce
around each argument with the empty string on sqlite and MySQL.
MySQL's CONCAT *does* return NULL if any argument is NULL, however it has
a very similar function, CONCAT_WS that just silently skips NULLs.
Therefore it can be used rather than unnecessary COALESCE calls:
https://dev.mysql.com/doc/refman/5.5/en/string-functions.html
#function_concat-ws
I've implemented this in a patch - it's not a big change.
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Ticket URL: <https://code.djangoproject.com/ticket/24609>
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Django
Reporter: adamchainz | Owner:
Type: | adamchainz
Cleanup/optimization | Status: assigned
Component: Database layer | Version: 1.8
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by adamchainz):
* status: new => assigned
* needs_better_patch: => 0
* owner: nobody => adamchainz
* needs_tests: => 0
* needs_docs: => 0
Comment:
https://github.com/django/django/pull/4468
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Ticket URL: <https://code.djangoproject.com/ticket/24609#comment:1>
Django
Reporter: adamchainz | Owner:
Type: | adamchainz
Cleanup/optimization | Status: assigned
Component: Database layer | Version: 1.8
(models, ORM) |
Severity: Normal | Resolution:
| Unreviewed
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Comment (by adamchainz):
"runtests.py db_functions" passes with MySQL 5.6 locally.
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Ticket URL: <https://code.djangoproject.com/ticket/24609#comment:2>
Django
Reporter: adamchainz | Owner:
Type: | adamchainz
Cleanup/optimization | Status: assigned
Component: Database layer | Version: 1.8
(models, ORM) |
Severity: Normal | Resolution:
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Changes (by timgraham):
* stage: Unreviewed => Ready for checkin
Comment:
Looks okay to me (but not a MySQL user). Could someone else +1?
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Ticket URL: <https://code.djangoproject.com/ticket/24609#comment:3>
Django
Reporter: adamchainz | Owner:
Type: | adamchainz
Component: Database layer | Version: 1.8
(models, ORM) |
Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Changes (by Tim Graham <timograham@…>):
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"9d0c600d8d6359107cdbef5f0c30757321da09f6" 9d0c600]:
{{{
#!CommitTicketReference repository=""
revision="9d0c600d8d6359107cdbef5f0c30757321da09f6"
Fixed #24609 -- Made ConcatPair use CONCAT_WS() on MySQL
}}}
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Ticket URL: <https://code.djangoproject.com/ticket/24609#comment:4>