django.db.utils.IntegrityError: CHECK constraint failed

Question

when I am migrating I am getting the error django.db.utils.IntegrityError: CHECK constraint failed. I am using django-cms. this error popped up after trying to add editor.js to the project

full Error:

  Applying advita.0003_auto_20220615_1506...Traceback (most recent call last):
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\sqlite3\base.py", line 413, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: CHECK constraint failed: (JSON_VALID("sub_title") OR "sub_title" IS NULL)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File ".\manage.py", line 22, in <module>
    main()
  File ".\manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\core\management\commands\migrate.py", line 243, in handle
    post_migrate_state = executor.migrate(
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\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 "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\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 "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\migrations\executor.py", line 227, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\migrations\operations\fields.py", line 236, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\sqlite3\schema.py", line 138, in alter_field
    super().alter_field(model, old_field, new_field, strict=strict)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\base\schema.py", line 571, in alter_field
    self._alter_field(model, old_field, new_field, old_type, new_type,
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\sqlite3\schema.py", line 360, in _alter_field
    self._remake_table(model, alter_field=(old_field, new_field))
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\sqlite3\schema.py", line 283, in _remake_table
    self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\base\schema.py", line 142, in execute
    cursor.execute(sql, params)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 98, in execute
    return super().execute(sql, params)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 66, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 75, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\mulla\AppData\Local\Programs\Python\Python38\lib\site-packages\django\db\backends\sqlite3\base.py", line 413, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: CHECK constraint failed: (JSON_VALID("sub_title") OR "sub_title" IS NULL)

Can anyone clarify why I am getting this error?

Answer 1

This is happening because field 'sub_title' has values earlier which are not valid json.

Table probably already has values for 'sub_title' field and you are changing trying to change earlier fieldtype to jsonfield if this is the case, you should update all values to valid json first.

Answer 2

You Faced This IntergrityError Because Your model sub_title does not have a null Field and You Direct do Change JsonField.

JsonField required null=True and Previous Field (sub_title) doesn't have null=True which means you have some value in those filed. After your migrations that Field already has value in the String for that reason, you got this error

django.db.utils.IntegrityError: CHECK constraint failed: (JSON_VALID("sub_title") OR "sub_title" IS NULL)

put that same Previous field and Add Constraint Null=True then apply migration after successful migration used then remove all Value from those Filed

Then You Change CharFiled to JsonField with constraint Null=True, Blank=True

JSONField(_("Sub Title"), blank=True, null=True)

Then apply Migration. it will definitely help you resolve this problem.