【django admin】外键关联中，如何选择一种属性后展示另外一种属性

class Money(admin.ModelAdmin):

    list_display = ('user','get_idcad','chuqin','qingjia','chizao','yingde','shide','remark',)
    list_filter = ['user','chuqin','qingjia','chizao','yingde','shide',]

    # 外键关联中，如何选择一种属性后展示另外一种属性
    def get_idcad(self, obj):
        return obj.gongzi.idcad        # 这是我们要展示的字段

    get_idcad.short_description = '工资卡号'
    get_idcad.admin_order_field = 'gongzi__idcad'

admin.site.register(models.Money, Money)




数据库设计： 定义外键关联 

class GgongZiID(models.Model):

    user = models.ForeignKey(to="UserInfo", verbose_name="所属员工", on_delete=models.CASCADE)
    idcad = models.CharField(verbose_name="工资卡号",max_length=55)

    def __str__(self):
        return self.user.name

    class Meta:
        verbose_name = "工资卡列表"
        verbose_name_plural = verbose_name
        db_table = 'GgongZiID'

class Money(models.Model):

    user = models.ForeignKey(to="UserInfo", verbose_name="员工姓名",on_delete=models.CASCADE)
    gongzi = models.ForeignKey(to="GgongZiID", verbose_name="工资卡号",on_delete=models.CASCADE)
    chuqin = models.IntegerField(verbose_name="出勤天数")
    qingjia = models.IntegerField(verbose_name="请假天数")
    chizao = models.IntegerField(verbose_name="迟到早退总数")
    yingde = models.FloatField(verbose_name="应得工资")
    shide = models.FloatField(verbose_name="实得工资")
    remark = models.TextField(max_length=255,verbose_name="备注")

    def __str__(self):
        return self.user.name

    class Meta:
        verbose_name = "工资条"
        verbose_name_plural = verbose_name
        db_table = 'Money'

目的：要通过选择工资员工的姓名，保存后展示选择工资姓名的工资卡号