【发布时间】：2021-01-09 08:44:46
【问题描述】：
我删除了所有应用程序中的 db.sqlite3 和所有 migrations/* 文件，除了 initial.py 文件。之后我尝试运行命令
python3.8 manage.py makemigrations product
之后我运行了命令
python3.8 manage.py migrate product
我收到以下错误：
sql SELECT "django_migrations"."id", "django_migrations"."app", "django_migrations"."name", "django_migrations"."applied" FROM "django_migrations"
param ()
self.cursor.execute() <django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x7f876c374dc0>
sql SELECT "django_migrations"."id", "django_migrations"."app", "django_migrations"."name", "django_migrations"."applied" FROM "django_migrations"
param ()
self.cursor.execute() <django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x7f876c374dc0>
Operations to perform:
Apply all migrations: product
Running migrations:
Applying product.0001_initial...sql INSERT INTO "django_migrations" ("app", "name", "applied") VALUES (%s, %s, %s)
param ['product', '0001_initial', '2020-09-23 06:05:03.633327']
self.cursor.execute() <django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x7f876c30ddc0>
sql CREATE INDEX "product_product_category_id_0c725779" ON "product_product" ("category_id")
param ()
self.cursor.execute() <django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x7f876c30db80>
Traceback (most recent call last):
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/sqlite3/base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: index product_product_category_id_0c725779 already exists
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 21, in <module>
main()
File "manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
utility.execute()
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/base.py", line 328, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/base.py", line 369, in execute
output = self.handle(*args, **options)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/core/management/commands/migrate.py", line 231, in handle
post_migrate_state = executor.migrate(
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/migrations/executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/migrations/executor.py", line 247, in apply_migration
migration_recorded = True
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/sqlite3/schema.py", line 36, in __exit__
super().__exit__(exc_type, exc_value, traceback)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/base/schema.py", line 115, in __exit__
self.execute(sql)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/base/schema.py", line 142, in execute
cursor.execute(sql, params)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 103, in execute
return super().execute(sql, params)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/sqlite3/base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: index product_product_category_id_0c725779 already exists
当我试图理解错误时，它说索引已经存在，所以我想通过 shell 检查数据库。我发现在 db.sqlite3 中创建了两个表，一个 id django_migrations 和 category_category。我试图获取这两个表的索引，但没有索引存在。然后如果表 product_product 不存在，为什么我会收到此错误。 这是shell命令的输出。
sqlite> .tables
category_category django_migrations
sqlite> drop index index product_product_category_id_0c725779;
Error: near "index": syntax error
sqlite> drop index index product_product_category_id_0c725779;
Error: near "index": syntax error
sqlite> drop index product_product_category_id_0c725779;
Error: no such index: product_product_category_id_0c725779
sqlite> .tables
category_category django_migrations
sqlite> .schema django_migrations
CREATE TABLE IF NOT EXISTS "django_migrations" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "app" varchar(255) NOT NULL, "name" varchar(255) NOT NULL, "applied" datetime NOT NULL);
sqlite> select * from django_migrations limit 10;
1|category|0001_initial|2020-09-23 06:04:19.853119
2|category|0001_initial|2020-09-23 06:04:19.853119
sqlite> .mode columns
sqlite> select * from django_migrations limit 10;
1 category 0001_initial 2020-09-23 06:04:19.853119
2 category 0001_initial 2020-09-23 06:04:19.853119
sqlite> drop index category_category.product_product_category_id_0c725779
...> drop index category_category.product_product_category_id_0c725779;
Error: near "drop": syntax error
sqlite> drop index category_category.product_product_category_id_0c725779;
Error: no such index: category_category.product_product_category_id_0c725779
sqlite> PRAGMA index_list('category_category');
sqlite> PRAGMA index_list('django_migrations');
sqlite> .schema category_category
CREATE TABLE IF NOT EXISTS "category_category" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "name" varchar(50) NOT NULL, "description" varchar(250) NOT NULL, "created_at" date NOT NULL, "updated_at" date NOT NULL);
sqlite> create index name_index on category_category(name);
sqlite> PRAGMA index_list('category_category');
0 name_index 0 c 0
sqlite> drop index category_category.name_index
...> drop index category_category.name_index;
Error: near "drop": syntax error
sqlite> drop index category_category.name_index;
Error: no such index: category_category.name_index
sqlite> drop index name_index;
sqlite> PRAGMA index_list('category_category');
sqlite> PRAGMA index_list('django_migrations');
【问题讨论】：
标签： django sqlite indexing model migration