django后台模型字段无法显示？

Question

django后台中有一个模型的所有字段无法显示，也无法在后台中手动添加该模型新记录。用shell查看数据库，发现数据存在，应用也运行正常。其余模型均能正常显示，不知道什么原因。django版本是1.11

models.py

from django.db import models

class User(models.Model):
        openid = models.CharField(max_length=20)
        nickname = models.CharField(max_length=20,null=True)
        def __str__(self):
                return self.nickname

class Record(models.Model):
        expression = models.CharField(max_length=100)
        user = models.ForeignKey(User)
        time = models.DateTimeField(auto_now_add=True)
        def __str__(self):
                return self.expression

admin.py

from django.contrib import admin
from .models import User,Record

class RecordAdmin(admin.ModelAdmin):
        list_display = ('expression','user','time')

class UserAdmin(admin.ModelAdmin):
        empty_value_display = "空"
        list_display = ('openid','nickname')

admin.site.register(User,UserAdmin)
admin.site.register(Record,RecordAdmin)

Answer 1

https://stackoverflow.com/que...