Django迁移中的索引已存在错误

如何解决Django迁移中的索引已存在错误

我删除了除initial.py文件以外的所有应用程序中的db.sqlite3和所有migrations / *文件。之后，我尝试运行命令

python3.8 manage.py makemigrations product

之后我运行命令

python3.8 manage.py migrate product

我遇到以下错误：

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"."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,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,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,many,context)
  File "/home/arjun-singh/.local/share/virtualenvs/pip_env_test-RsPmIzoy/lib/python3.8/site-packages/django/db/backends/utils.py",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",params)
django.db.utils.OperationalError: index product_product_category_id_0c725779 already exists

当我尝试理解该错误时，它说该索引已经存在，因此我想通过外壳检查数据库。我发现在db.sqlite3中创建了两个表，一个ID为 django_migrations 和 category_category 。我试图获取两个表的索引，但是都没有索引。如果表product_product不存在，为什么会出现此错误。 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');

解决方法

1。打开数据库db.sqlite3。 2.删除行：$str=file_get_contents('style.css'); //replace something in the file string - this is a VERY simple example $str=str_replace("color:blue;","color:red",$str); //write the entire string file_put_contents('style.css',$str); 3.重新运行python manage.py migration。