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Django清空所有数据或重置migrations同步

admin2019年1月8日 22:45 【Django 】 1339人已围观

# Django重置migration ## 清空数据库 **不需要原有的数据库数据** 1. 删除数据库所有的表 2. 删除项目的migrations模块中的所有文件，除了`__init__.py` 文件 3. 运行命令 ```bash python manage.py makemigrations python manage.py migrate ``` ## 重置migrations **不想要删除现有的数据库，只是想重新建立 migrations 文件**，强迫症的福音 ### 重置所有步骤 ```bash manage.py@StarMeow > makemigrations manage.py@StarMeow > showmigrations casual manage.py@StarMeow > migrate --fake casual zero # 步骤 manage.py@StarMeow > showmigrations casual # 手动删除文件 manage.py@StarMeow > makemigrations casual # 步骤 manage.py@StarMeow > migrate --fake-initial casual # 步骤 ``` ### 检查同步保证目前的`migrations`文件和数据库是同步的，通过执行 ```bash manage.py@StarMeow > makemigrations # 如果看到这样的提示: No changes detected，则可以继续接下来的步骤 ``` ### 查看所有已生效migrations文件可以看到当前项目，所有的app及对应的已经生效的migrations文件如 ```bash manage.py@StarMeow > showmigrations admin [X] 0001_initial [X] 0002_logentry_remove_auto_add [X] 0003_logentry_add_action_flag_choices assets [X] 0001_initial [X] 0002_auto_20181205_0926 [X] 0003_floorareaseat auth [X] 0001_initial [X] 0002_alter_permission_name_max_length [X] 0003_alter_user_email_max_length blog [X] 0001_initial [X] 0002_blogcomment [X] 0003_auto_20180821_1231 captcha [X] 0001_initial casual [X] 0001_initial [X] 0002_auto_20180922_1548 [X] 0003_auto_20180922_1549 contenttypes [X] 0001_initial [X] 0002_remove_content_type_name coolqbot (no migrations) log [X] 0001_initial [X] 0002_auto_20181115_2114 [X] 0003_blogdailytimes problem [X] 0001_initial [X] 0002_auto_20181225_1924 [X] 0003_auto_20181228_1529 pxectrl [X] 0001_initial [X] 0002_auto_20181230_1523 [X] 0003_auto_20190102_1547 reversion [X] 0001_squashed_0004_auto_20160611_1202 schedule [X] 0001_initial [X] 0002_auto_20181126_1338 [X] 0003_auto_20181126_1900 sessions [X] 0001_initial simpleauth [X] 0001_initial [X] 0002_auto_20181206_1126 [X] 0003_simpleconfigure supervise [X] 0001_initial [X] 0002_auto_20181217_1206 usercenter [X] 0001_initial [X] 0002_auto_20180820_1418 [X] 0003_userpermission webchat (no migrations) xadmin [X] 0001_initial [X] 0002_log [X] 0003_auto_20160715_0100 ``` ### 查看某个应用已生效migrations文件只查看某个应用 ```bash manage.py@StarMeow > showmigrations casual casual [X] 0001_initial [X] 0002_auto_20180922_1548 [X] 0003_auto_20180922_1549 [X] 0004_auto_20180922_1559 [X] 0005_auto_20180923_0950 [X] 0006_auto_20180924_1633 [X] 0007_buyerinfo_group_name [X] 0008_auto_20181202_1701 [X] 0009_auto_20181202_1719 [X] 0010_auto_20181217_1206 [X] 0011_auto_20181217_1311 [X] 0012_auto_20181217_1428 [X] 0013_auto_20181217_1429 [X] 0014_auto_20181217_1430 [X] 0015_auto_20181217_1728 [X] 0016_works_url [X] 0017_auto_20181217_1741 [X] 0018_auto_20181218_1307 [X] 0019_auto_20181218_1358 [X] 0020_auto_20181219_1315 [X] 0021_auto_20181219_1706 [X] 0022_auto_20181221_2322 [X] 0023_auto_20190108_1234 ``` ### 开始重置某个应用 ``` manage.py@StarMeow > migrate --fake casual zero Operations to perform: Unapply all migrations: casual Running migrations: Rendering model states... DONE Unapplying casual.0023_auto_20190108_1234... FAKED Unapplying casual.0022_auto_20181221_2322... FAKED Unapplying casual.0021_auto_20181219_1706... FAKED Unapplying casual.0020_auto_20181219_1315... FAKED Unapplying casual.0019_auto_20181218_1358... FAKED Unapplying casual.0018_auto_20181218_1307... FAKED Unapplying casual.0017_auto_20181217_1741... FAKED Unapplying casual.0016_works_url... FAKED Unapplying casual.0015_auto_20181217_1728... FAKED Unapplying casual.0014_auto_20181217_1430... FAKED Unapplying casual.0013_auto_20181217_1429... FAKED Unapplying casual.0012_auto_20181217_1428... FAKED Unapplying casual.0011_auto_20181217_1311... FAKED Unapplying casual.0010_auto_20181217_1206... FAKED Unapplying casual.0009_auto_20181202_1719... FAKED Unapplying casual.0008_auto_20181202_1701... FAKED Unapplying casual.0007_buyerinfo_group_name... FAKED Unapplying casual.0006_auto_20180924_1633... FAKED Unapplying casual.0005_auto_20180923_0950... FAKED Unapplying casual.0004_auto_20180922_1559... FAKED Unapplying casual.0003_auto_20180922_1549... FAKED Unapplying casual.0002_auto_20180922_1548... FAKED Unapplying casual.0001_initial... FAKED ``` 这里的 `casual`就是你要重置的app ### 查看重置后的状态之后再执行 `python manage.py showmigrations`，你会发现文件前的 [x] 变成了[ ] ```bash manage.py@StarMeow > showmigrations casual casual [ ] 0001_initial [ ] 0002_auto_20180922_1548 [ ] 0003_auto_20180922_1549 [ ] 0004_auto_20180922_1559 [ ] 0005_auto_20180923_0950 [ ] 0006_auto_20180924_1633 [ ] 0007_buyerinfo_group_name [ ] 0008_auto_20181202_1701 [ ] 0009_auto_20181202_1719 [ ] 0010_auto_20181217_1206 [ ] 0011_auto_20181217_1311 [ ] 0012_auto_20181217_1428 [ ] 0013_auto_20181217_1429 [ ] 0014_auto_20181217_1430 [ ] 0015_auto_20181217_1728 [ ] 0016_works_url [ ] 0017_auto_20181217_1741 [ ] 0018_auto_20181218_1307 [ ] 0019_auto_20181218_1358 [ ] 0020_auto_20181219_1315 [ ] 0021_auto_20181219_1706 [ ] 0022_auto_20181221_2322 [ ] 0023_auto_20190108_1234 ``` ### 删除migrations文件夹下的文件现在，你可以删除`casual` 这个 app下的migrations模块中除 `__init__.py` 之外的所有文件。 ### 重新生成migrations文件之后，执行 ```bash manage.py@StarMeow > makemigrations casual Migrations for 'casual': apps\casual\migrations\0001_initial.py - Create model BuyerInfo - Create model Category - Create model Discount - Create model GroupBuyingInfo - Create model GroupBuyingWorks - Create model Phase - Create model PostageLink - Create model PostageTemplate - Create model PurchaseOrder - Create model PurchaseRecord - Create model Works - Add field works to purchaserecord - Add field works to groupbuyingworks - Add field phase to groupbuyinginfo - Add field phase to discount - Alter unique_together for works (1 constraint(s)) - Alter unique_together for discount (1 constraint(s)) ``` 程序会再次为这个app 生成 `0001_initial.py` 之类的文件 ### 重要：重置migrations到数据库 **最重要的一步来了**, 执行 ```bash manage.py@StarMeow > migrate --fake-initial casual Operations to perform: Apply all migrations: casual Running migrations: Applying casual.0001_initial... FAKED ``` `--fake-initial`会在数据库中的 migrations表中记录当前这个app 执行到 `0001_initial.py` ，但是它不会真的执行该文件中的代码。这样就做到了，既不对现有的数据库改动，而又可以重置 migraion 文件参考：https://simpleisbetterthancomplex.com/tutorial/2016/07/26/how-to-reset-migrations.html # 英文文档 ## Scenario 1: The project is still in the development environment and you want to perform a full clean up. You don’t mind throwing the whole database away. ### 1. Remove the all migrations files within your project Go through each of your projects apps migration folder and remove everything inside, except the `__init__.py`file. Or if you are using a unix-like OS you can run the following script (inside your project dir): ```bash find . -path "*/migrations/*.py" -not -name "__init__.py" -delete find . -path "*/migrations/*.pyc" -delete ``` ### 2. Drop the current database, or delete the `db.sqlite3` if it is your case. ### 3. Create the initial migrations and generate the database schema: ```bash python manage.py makemigrations python manage.py migrate ``` And you are good to go. *** ## Scenario 2: You want to clear all the migration history but you want to keep the existing database. ### 1. Make sure your models fits the current database schema The easiest way to do it is trying to create new migrations: ```bash python manage.py makemigrations ``` If there are any pending migration, apply them first. If you see the message: ```bash No changes detected ``` You are good to go. ### 2. Clear the migration history for each app Now you will need to clear the migration history app by app. First run the `showmigrations` command so we can keep track of what is going on: ```bash $ python manage.py showmigrations ``` Result: ```bash admin [X] 0001_initial [X] 0002_logentry_remove_auto_add 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 contenttypes [X] 0001_initial [X] 0002_remove_content_type_name core [X] 0001_initial [X] 0002_remove_mymodel_i [X] 0003_mymodel_bio sessions [X] 0001_initial ``` Clear the migration history (please note that **core** is the name of my app): ```bash $ python manage.py migrate --fake core zero ``` The result will be something like this: ```bash Operations to perform: Unapply all migrations: core Running migrations: Rendering model states... DONE Unapplying core.0003_mymodel_bio... FAKED Unapplying core.0002_remove_mymodel_i... FAKED Unapplying core.0001_initial... FAKED ``` Now run the command `showmigrations` again: ```bash $ python manage.py showmigrations ``` Result: ```bash admin [X] 0001_initial [X] 0002_logentry_remove_auto_add 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 contenttypes [X] 0001_initial [X] 0002_remove_content_type_name core [ ] 0001_initial [ ] 0002_remove_mymodel_i [ ] 0003_mymodel_bio sessions [X] 0001_initial ``` You must do that for all the apps you want to reset the migration history. ### 3. Remove the actual migration files. Go through each of your projects apps migration folder and remove everything inside, except for the `__init__.py` file. Or if you are using a unix-like OS you can run the following script (inside your project dir): ```bash find . -path "*/migrations/*.py" -not -name "__init__.py" -delete find . -path "*/migrations/*.pyc" -delete ``` PS: The example above will remove all the migrations file inside your project. Run the `showmigrations` again: ```bash $ python manage.py showmigrations ``` Result: ```bash admin [X] 0001_initial [X] 0002_logentry_remove_auto_add 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 contenttypes [X] 0001_initial [X] 0002_remove_content_type_name core (no migrations) sessions [X] 0001_initial ``` ### 4. Create the initial migrations ```bash $ python manage.py makemigrations ``` Result: ```bash Migrations for 'core': 0001_initial.py: - Create model MyModel ``` ### 5. Fake the initial migration In this case you won’t be able to apply the initial migration because the database table already exists. What we want to do is to fake this migration instead: ```bash $ python manage.py migrate --fake-initial ``` Result: ```bash Operations to perform: Apply all migrations: admin, core, contenttypes, auth, sessions Running migrations: Rendering model states... DONE Applying core.0001_initial... FAKED ``` Run `showmigrations` again: ```bash admin [X] 0001_initial [X] 0002_logentry_remove_auto_add 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 contenttypes [X] 0001_initial [X] 0002_remove_content_type_name core [X] 0001_initial sessions [X] 0001_initial ``` And we are all set up :-)