Opened 10 years ago
Closed 10 years ago
#23679 closed Bug (fixed)
varchar(255) converted into varchar(255) NOT NULL after inspectdb followed by migrate
Reported by: | Paul Dejean | Owned by: | nobody |
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Component: | Core (Management commands) | Version: | 1.7 |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Ready for checkin | |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
show create table on the original database yields:
device_mac_ethernet
varchar(255) DEFAULT NULL
inspectdb convert this into:
models.CharField(max_length=255, blank=True)
makemigrations followed by migrate converts that into:
device_mac_ethernet
varchar(255) NOT NULL
Change History (9)
comment:2 by , 10 years ago
Triage Stage: | Unreviewed → Accepted |
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Type: | Uncategorized → Bug |
The fact that inspectdb
doesn't add null=True
on CharField
s/TextField
s is based on a Django "good practice", explained in https://docs.djangoproject.com/en/stable/ref/models/fields/#null
Now the question is, should inspectdb
reflect the current database structure as faithfully as possible, or should it entice users to follow good practices? At a minimum, Django should add a comment that it has not respected the NULL flag on the introspected field. Accepted the ticket on that base.
comment:3 by , 10 years ago
How about adding a command line option to inspectdb so the user can choose. Good practice being enforced can be the default but users who need to deviate for some reason can do so without having to hack the inspectdb source as I did.
comment:4 by , 10 years ago
inspectdb output has to be reviewed in all cases. For me, the choice is:
- keep the current output and add a comment like:
# Field was detected as NULL, but we didn't add null=True, see https://docs.djangoproject.com/en/stable/ref/models/fields/#null
- change the output to let
null=True
and add the comment:# Read https://docs.djangoproject.com/en/stable/ref/models/fields/#null and consider removing null=True
I'm currently favoring the second option.
comment:5 by , 10 years ago
Given those two choices, I'm in favor of the second option as well, though I don't even think the comment is really necessary.
I think Django's advice re null CharFields is questionable, but even if we accept that advice, a CharField(null=True)
is still a valid, functional configuration, and there is no reason for inspectdb
to prohibit it and intentionally generate models that don't match the source database.
comment:8 by , 10 years ago
Triage Stage: | Accepted → Ready for checkin |
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comment:9 by , 10 years ago
Resolution: | → fixed |
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Status: | new → closed |
If I had to guess this is a case of: hey "varchar(255) .* NULL" totally matches "varchar(255) NOT NULL"
Also I might submit a patch for this *fingers crossed*