Django转向PostgreSQL无法导入数据,说明数据太长

$python manage.py loaddata fixtures/core.json fixtures/auth.json

Installing json fixture 'fixtures/core' from absolute path.
Problem installing fixture 'fixtures/core.json': Traceback (most recent call last):
  File "/home/mvid/webapps/nihl/nihlapp/django/core/management/commands/loaddata.py",line 153,in handle
    obj.save()
  File "/home/mvid/webapps/nihl/nihlapp/django/core/serializers/base.py",line 163,in save
    models.Model.save_base(self.object,raw=True)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/models/base.py",line 495,in save_base
    result = manager._insert(values,return_id=update_pk)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/models/manager.py",line 177,in _insert
    return insert_query(self.model,values,**kwargs)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/models/query.py",line 1087,in insert_query
    return query.execute_sql(return_id)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/models/sql/subqueries.py",line 320,in execute_sql
    cursor = super(InsertQuery,self).execute_sql(None)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/models/sql/query.py",line 2369,in execute_sql
    cursor.execute(sql,params)
  File "/home/mvid/webapps/nihl/nihlapp/django/db/backends/util.py",line 19,in execute
    return self.cursor.execute(sql,params)
DataError: value too long for type character varying(30)

我从来没有习惯得到任何数据长度错误,我没有改变数据库交换机之间的模型. PostgreSQL正在运行utf8.有没有办法确切地看到它失败的json值,以便我可以更新各自的模型？任何想法为什么值在SQLite中工作但在PostgreSQL中失败？