Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
-+-
 Reporter:  Jacob Walls  |Owner:  Simon
 Type:   |  Charette
  Cleanup/optimization   |   Status:  closed
Component:  Migrations   |  Version:  dev
 Severity:  Normal   |   Resolution:  fixed
 Keywords:   | Triage Stage:  Ready for
 |  checkin
Has patch:  1|  Needs documentation:  0
  Needs tests:  0|  Patch needs improvement:  0
Easy pickings:  0|UI/UX:  0
-+-
Changes (by Mariusz Felisiak ):

 * status:  assigned => closed
 * resolution:   => fixed


Comment:

 In [changeset:"5896aa8367d545c60bb544c31d7ecaaecc321045" 5896aa8]:
 {{{
 #!CommitTicketReference repository=""
 revision="5896aa8367d545c60bb544c31d7ecaaecc321045"
 Fixed #33197 -- Made field rename with prior matching db_column change a
 noop.

 Thanks Jacob Walls for the report.
 }}}

-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.1871c987117b0bfb4edefadd4aa97354%40djangoproject.com.

Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
-+-
 Reporter:  Jacob Walls  |Owner:  Simon
 Type:   |  Charette
  Cleanup/optimization   |   Status:  assigned
Component:  Migrations   |  Version:  dev
 Severity:  Normal   |   Resolution:
 Keywords:   | Triage Stage:  Ready for
 |  checkin
Has patch:  1|  Needs documentation:  0
  Needs tests:  0|  Patch needs improvement:  0
Easy pickings:  0|UI/UX:  0
-+-
Changes (by Mariusz Felisiak):

 * stage:  Accepted => Ready for checkin


-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.cc58f94a4f996dd06f8318f38b6fe2e3%40djangoproject.com.

Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
-+-
 Reporter:  Jacob Walls  |Owner:  Simon
 Type:   |  Charette
  Cleanup/optimization   |   Status:  assigned
Component:  Migrations   |  Version:  dev
 Severity:  Normal   |   Resolution:
 Keywords:   | Triage Stage:  Accepted
Has patch:  1|  Needs documentation:  0
  Needs tests:  0|  Patch needs improvement:  0
Easy pickings:  0|UI/UX:  0
-+-
Changes (by Simon Charette):

 * owner:  nobody => Simon Charette
 * status:  new => assigned


-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.29c6352ae5196b4ca185ec2b980568d4%40djangoproject.com.

Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
--+
 Reporter:  Jacob Walls   |Owner:  nobody
 Type:  Cleanup/optimization  |   Status:  new
Component:  Migrations|  Version:  dev
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  0
  Needs tests:  0 |  Patch needs improvement:  0
Easy pickings:  0 |UI/UX:  0
--+
Changes (by Simon Charette):

 * has_patch:  0 => 1


-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.389ceb87d507309d1a50909a8c020057%40djangoproject.com.

Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
--+
 Reporter:  Jacob Walls   |Owner:  nobody
 Type:  Cleanup/optimization  |   Status:  new
Component:  Migrations|  Version:  dev
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  0 |  Needs documentation:  0
  Needs tests:  0 |  Patch needs improvement:  0
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Simon Charette):

 You'll want to adjust `AlterField.name` accordingly if you swap the order
 of operations; change `name='core_renamed'` to `name='core'`.

 {{{#!python
 operations = [
 migrations.AlterField(
 model_name='apple',
 name='core',
 field=models.BooleanField(db_column='core'),
 ),
 migrations.RenameField(
 model_name='apple',
 old_name='core',
 new_name='core_renamed',
 ),
 ]
 }}}

-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.22946d58f15364855056c3b98de4a882%40djangoproject.com.

Re: [Django] #33197: Renaming field and providing prior field name to db_column should be an SQL noop (was: Providing prior implicit field name to db_column should be a noop)

[Django]

#33197: Renaming field and providing prior field name to db_column should be an 
SQL
noop
--+
 Reporter:  Jacob Walls   |Owner:  nobody
 Type:  Cleanup/optimization  |   Status:  new
Component:  Migrations|  Version:  dev
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  0 |  Needs documentation:  0
  Needs tests:  0 |  Patch needs improvement:  0
Easy pickings:  0 |UI/UX:  0
--+

Old description:

> Similar to #31826, I would expect no migration changes detected when a
> `db_column` is added that matches the implicit field name. I tested with
> and without renaming the field on SQLite and MySQL 5.7.31. I'm not
> familiar enough with the review of #31826 to know whether these are
> distinct cases versus if it should be reopened.
>
> {{{
> class Apple(models.Model):
> core = models.BooleanField()
> }}}
>
> {{{
> class Apple(models.Model):
> core_renamed = models.BooleanField(db_column='core')
> }}}
> {{{
> Was apple.core renamed to apple.core_renamed (a BooleanField)? [y/N] y
> Migrations for 'renamez':
>   renamez/migrations/0002_rename_core_apple_core_renamed_and_more.py
> - Rename field core on apple to core_renamed
> - Alter field core_renamed on apple
> }}}
>
> `python manage.py sqlmigrate renamez 0002` showing unnecessary SQL:
> {{{
> BEGIN;
> --
> -- Rename field core on apple to core_renamed
> --
> ALTER TABLE "renamez_apple" RENAME COLUMN "core" TO "core_renamed";
> --
> -- Alter field core_renamed on apple
> --
> ALTER TABLE "renamez_apple" RENAME COLUMN "core_renamed" TO "core";
> COMMIT;
> }}}
>
> Without renaming the field, follow the same flow and get an `AlterField`
> migration without SQL:
>
> {{{
> BEGIN;
> --
> -- Alter field core on apple
> --
> COMMIT;
> }}}

New description:

 Renaming a field and setting the prior implicit field name as the
 `db_column` to avoid db operations creates a migration emitting
 unnecessary SQL. Similar to #31826, which handled a very similar scenario
 but where there is no field rename, I would expect a SQL noop. I tested
 with SQLite and MySQL 5.7.31.

 {{{
 class Apple(models.Model):
 core = models.BooleanField()
 }}}

 {{{
 class Apple(models.Model):
 core_renamed = models.BooleanField(db_column='core')
 }}}
 {{{
 Was apple.core renamed to apple.core_renamed (a BooleanField)? [y/N] y
 Migrations for 'renamez':
   renamez/migrations/0002_rename_core_apple_core_renamed_and_more.py
 - Rename field core on apple to core_renamed
 - Alter field core_renamed on apple
 }}}

 `python manage.py sqlmigrate renamez 0002` showing unnecessary SQL:
 {{{
 BEGIN;
 --
 -- Rename field core on apple to core_renamed
 --
 ALTER TABLE "renamez_apple" RENAME COLUMN "core" TO "core_renamed";
 --
 -- Alter field core_renamed on apple
 --
 ALTER TABLE "renamez_apple" RENAME COLUMN "core_renamed" TO "core";
 COMMIT;
 }}}

 Without renaming the field, follow the same flow and get an `AlterField`
 migration without SQL, which is what #31826 intended:

 {{{
 BEGIN;
 --
 -- Alter field core on apple
 --
 COMMIT;
 }}}

--

Comment (by Jacob Walls):

 Thanks for having a look. I see now the scope of #31826 was just for flows
 where the field is not renamed. So that makes this ticket a request to
 extend this to field renames, which looks like was discussed as 3 and 4
 [https://code.djangoproject.com/ticket/29245#comment:1 here].

 > I assume the issue goes away if you swap the order of operations in your
 migration?

 If I switch the order to have `AlterField` followed by `RenameField`,
 `FieldDoesNotExist` is raised when migrating. These are the operations:

 {{{
 operations = [
 migrations.RenameField(
 model_name='apple',
 old_name='core',
 new_name='core_renamed',
 ),
 migrations.AlterField(
 model_name='apple',
 name='core_renamed',
 field=models.BooleanField(db_column='core'),
 ),
 ]
 }}}

-- 
Ticket URL: 
Django 
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/073.e71ac5a87dc69b14fbb4e7cea5379da3%40djangoproject.com.