id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
29583	python manage.py inspectdb makes all fields with a default value blank=True, null=True	Kimball Leavitt	nobody	"Wasn't sure on the category or difficulty of fix, so logged it as an ""easy pickings bug"".

I'm using:

Ubuntu 16.04
Python 3.7.0
Django 2.0.4
Mariadb 10.2.16

Before I get into this, I realize that
-""Django is best suited for developing new applications""
-This probably isn't a huge deal or a high priority
...BUT I figured I'd submit this anyway while I was thinking about it. Maybe it'll save someone some extra work down the line.


Steps to reproduce:

1. Setup a legacy db in settings.py (see https://docs.djangoproject.com/en/2.0/howto/legacy-databases/)
-Prerequisite: you have a column in one of your tables that has a default value.
-Example: test_field int(11) DEFAULT 1
2. Run python manage.py inspectdb [--database DATABASE_NAME  [ TABLE ] ] > models.py (or don't include ""> models.py"" and you can view the results from the command line)
3. Open models.py
    -test_field will look something like this:
        {{{test_field = models.IntegerField(blank=True, null=True)}}}
    -What I would expect:
        {{{test_field = models.IntegerField(default=1)}}}

What I've been able to dig up:

# https://www.google.com/url?q=https%3A%2F%2Fgithub.com%2Fdjango%2Fdjango%2Fblob%2Fmaster%2Fdjango%2Fcore%2Fmanagement%2Fcommands%2Finspectdb.py%23L144&sa=D&sntz=1&usg=AFQjCNGZLkFkaqIJ1Ap1dhXRB0jARXcCoA
# from inspectdb.py (line 144, comments included in the original file, )


{{{
142  # Add 'null' and 'blank', if the 'null_ok' flag was present in the
143  # table description.
144  if row[6]:  # If it's NULL...
145      extra_params['blank'] = True
146      extra_params['null'] = True
}}}


# https://github.com/django/django/blob/master/django/db/backends/mysql/introspection.py#L95+info.column_default
# from introspection.py in get_field_description (line 95, comment is mine)


{{{
86  fields = []
87  for line in cursor.description:
88         info = field_info[line[0]]
89         fields.append(FieldInfo(
90               *line[:3],
91              to_int(info.max_len) or line[3],
92              to_int(info.num_prec) or line[4],
93              to_int(info.num_scale) or line[5],
94              line[6],
95              info.column_default, # THIS LINE IS JUST WHATEVER THE COLUMN DEFAULT IS
96              info.extra,
97              info.is_unsigned,
98          ))
99  return fields
}}}


I'm sure there are a lot of things I don't understand about this, but I don't think that having a default value should automatically add blank=True, null=True. 
Is having a default value really a ""'null_ok' flag""?

I think it should only put blank=True, null=True if the default is set to NULL in the column. Otherwise, it should set the default to whatever the default value is (ex: default=1)

Caveat: I've only tested this with int fields."	Bug	closed	Core (Management commands)	2.0	Normal	invalid	manage.py, inspectdb, models		Unreviewed	0	0	0	0	1	0