我有一个元组,我正试图在我的模型中用于选择字段。尽管如此,我创建的这个表没有最后一列(可选值-可以为null),我现在正试图添加它。这是我的型号代码
class SemesterData(models.Model):
YESNOCHOICE = (
('Y', 'Yes'),
('N', 'No'),
)
sid = models.ForeignKey(SessionData,on_delete=models.CASCADE)
semester_name = models.CharField(max_length=50)
status = models.CharField(max_length=3, choices=YESNOCHOICE, null=True, default=YESNOCHOICE[1][0])
def __str__(self):
return self.semester_name
我的跟踪显示
C:\Users\BOLADE\Desktop\django-project\clearance>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions, system
Running migrations:
Applying system.0002_auto_20190109_1729...Traceback (most recent call las
t):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\__init__.py", line 381, in execute_
from_command_line
utility.execute()
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\base.py", line 316, in run_from_arg
v
self.execute(*args,**cmd_options)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\base.py", line 353, in execute
output = self.handle(*args,**options)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args,**kwargs)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\core\management\commands\migrate.py", line 203, in
handle
fake_initial=fake_initial,
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\migrations\executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, f
ake_initial=fake_initial)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\migrations\executor.py", line 147, in _migrate_a
ll_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=
fake_initial)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\migrations\executor.py", line 244, in apply_migr
ation
state = migration.apply(state, schema_editor)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\migrations\migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, p
roject_state)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\migrations\operations\fields.py", line 216, in d
atabase_forwards
schema_editor.alter_field(from_model, from_field, to_field)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\backends\base\schema.py", line 523, in alter_fie
ld
old_db_params, new_db_params, strict)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\backends\base\schema.py", line 626, in _alter_fi
eld
old_default = self.effective_default(old_field)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\backends\base\schema.py", line 239, in effective
_default
return field.get_db_prep_save(default, self.connection)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\models\fields\__init__.py", line 790, in get_db_
prep_save
return self.get_db_prep_value(value, connection=connection, prepared=Fa
lse)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\models\fields\__init__.py", line 785, in get_db_
prep_value
value = self.get_prep_value(value)
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\l
ib\site-packages\django\db\models\fields\__init__.py", line 1807, in get_pr
ep_value
return int(value)
TypeError: int() argument must be a string, a bytes-like object or a number
, not 'tuple'
我将MySQL5与Django2.1和Python3.6一起使用。我在这个平台上尝试了以前的建议,但仍然显示出相同的错误。
失败的迁移
# Generated by Django 2.1.4 on 2019-01-09 16:29
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('system', '0001_initial'),
]
operations = [
migrations.AlterField(
model_name='semesterdata',
name='status',
field=models.CharField(choices=[('Y', 'Yes'), ('N', 'No')], default='N', max_length=3),
),
]
django 2.1.4于2019-01-08 20:00生成的0001_initial.py
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
initial = True
dependencies = [
]
operations = [
migrations.CreateModel(
name='DepartmentData',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('dept_name', models.CharField(max_length=50)),
('created_on', models.DateTimeField(auto_now_add=True)),
],
),
migrations.CreateModel(
name='FacultyData',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('faculty_name', models.CharField(max_length=30)),
('created_on', models.DateTimeField(auto_now_add=True)),
],
),
migrations.CreateModel(
name='SemesterData',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('semester_name', models.CharField(max_length=50)),
('status', models.IntegerField(choices=[('0', 'Yes'), ('1', 'No')], default=('1', 'No'))),
],
),
migrations.CreateModel(
name='SessionData',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('session_name', models.CharField(max_length=15)),
],
),
migrations.AddField(
model_name='semesterdata',
name='sid',
field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='system.SessionData'),
),
migrations.AddField(
model_name='departmentdata',
name='fid',
field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='system.FacultyData'),
),
]
2条答案
按热度按时间col17t5w1#
初始迁移中的默认值不正确。
把它改成
请注意,您需要进行数据迁移才能更改任何现有的
1
以及0
数据库中的值'Y'
或“n”。如果您刚刚开始项目,并且数据库中没有任何所需的数据,您可能会发现删除数据库、删除两个迁移,然后重新运行makemigrations和migrate是最简单的方法。
ffvjumwh2#
尝试使用模型选项。它更具可读性,你可以避免你的错误