ぶっつけ本番でDBを触るのはこわいので、検証をやってみました。
今回は、model.pyの変更を、データベースに反映させてみます。
最初のmodel.pyはこんな感じ。
model.py
from django.db import models
class Person(models.Model):
name = models.CharField("名前", max_length=100)
age = models.IntegerField("年齢")
def __str__(self):
return self.name
class Team(models.Model):
full_name = models.CharField("チーム名", max_length=100) ⬅️full_nameをnameに変更
members = models.ManyToManyField("Person", through="PersonTeamRelation", through_fields=("team", "person"))
def __str__(self):
return self.name
class PersonTeamRelation(models.Model):
team = models.ForeignKey("Team", models.DO_NOTHING)
person = models.ForeignKey("Person", models.DO_NOTHING)
joined_date = models.DateField(auto_now=False, auto_now_add=False)
Team.full_nameをTeam.nameに変更してmakemigrations, migrateしてみると。
bash.sh
Did you rename team.full_name to team.name (a CharField)? [y/N] y ⬅️本当にいいの？と聞かれる
Migrations for 'project':
project/migrations/0002_auto_20200206_1441.py
- Rename field full_name on team to name ⬅️どう変わったかの確認
>>> python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, project, sessions
Running migrations:
Applying project.0002_auto_20200206_1441... OK ⬅️projectに反映されたよ
>>> python manage.py showmigrations ⬅️これでマイグレーションの履歴がみれる
admin
[X] 0001_initial
[X] 0002_logentry_remove_auto_add
[X] 0003_logentry_add_action_flag_choices
auth
[X] 0001_initial
[X] 0002_alter_permission_name_max_length
[X] 0003_alter_user_email_max_length
[X] 0004_alter_user_username_opts
[X] 0005_alter_user_last_login_null
[X] 0006_require_contenttypes_0002
[X] 0007_alter_validators_add_error_messages
[X] 0008_alter_user_username_max_length
[X] 0009_alter_user_last_name_max_length
[X] 0010_alter_group_name_max_length
[X] 0011_update_proxy_permissions
contenttypes
[X] 0001_initial
[X] 0002_remove_content_type_name
project
[X] 0001_initial
[X] 0002_auto_20200206_1441 ⬅️今回やったマイグレーション
sessions
[X] 0001_initial
上手くいったので、思い切ってテーブルを増やしてみた。
model.py
from django.db import models
class User(models.Model):
name = models.CharField("名前", max_length=100)
age = models.IntegerField("年齢")
def __str__(self):
return self.name
class TeamProfile(models.Model):
user = models.OneToOneField(User, related_name="profile", on_delete=models.CASCADE)
score = models.IntegerField(default=0)
created_at = models.DateTimeField(auto_now=True)
class Team(models.Model):
name = models.CharField("チーム名", max_length=100)
members = models.ManyToManyField("User", through="UserTeamRelation", through_fields=("team", "user"))
def __str__(self):
return self.name
class UserTeamRelation(models.Model):
team = models.ForeignKey("Team", models.DO_NOTHING)
user = models.ForeignKey("User", models.DO_NOTHING)
joined_date = models.DateField(auto_now=False, auto_now_add=False)
bash.sh
>>> python manage.py makemigrations
Did you rename the project.Person model to User? [y/N] y
Did you rename the project.PersonTeamRelation model to UserTeamRelation? [y/N] y
Did you rename userteamrelation.person to userteamrelation.user (a ForeignKey)? [y/N] y
Migrations for 'project':
project/migrations/0003_auto_20200206_1501.py
- Rename model PersonTeamRelation to UserTeamRelation
- Rename field person on userteamrelation to user
- Rename model Person to User
- Create model TeamProfile
>>> python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, project, sessions
Running migrations:
Applying project.0003_auto_20200206_1501... OK
>>> python manage.py makemigrations
Migrations for 'project':
project/migrations/0004_auto_20200206_1503.py
- Alter field score on teamprofile