admin添加用户时报错：(1452, 'Cannot add or update a child row: a foreign key constraint fails (`mxonline`.`django_admin_l

在stackoverflow找到答案：

DATABASES = {
'default': {
    ...         
    'OPTIONS': {
         "init_command": "SET foreign_key_checks = 0;",
    },
 }
}

(According to the official doc) In previous versions of Django, fixtures with forward references (i.e. relations to rows that have not yet been inserted into the database) would fail to load when using the InnoDB storage engine. This was due to the fact that InnoDB deviates from the SQL standard by checking foreign key constraints immediately instead of deferring the check until the transaction is committed. This problem has been resolved in Django 1.4.