使用Django通用视图创建Station时遇IntegrityError问题求助

• 移除user外键后，触发错误：

  IntegrityError at /station/Add/
  (1048, "Column 'user_type_id' cannot be null")

• 不设置user_type时，点击提交按钮后表单自动刷新且内容清空

相关代码 #

station/views.py #

class StationCreateView(LoginRequiredMixin, CreateView):
    model = Station
    fields = ('station_name', 'station_address','connectors','status', 'start_time','end_time','open_day', 
                'state', 'city', 'area', 'user')
    template_name = 'owner/add_station.html'

    def form_valid(self, form):
        form.instance.user = self.request.user
        return super().form_valid(form)

station/models.py #

class Station(models.Model):    
STAUTUS_CHOICE = (
    ("ACTIVE", "ACTIVE"),
    ("INACTIVE", "INACTIVE")
    )
DAY_CHOICE = (
    ("MONDAY", "MONDAY"),
    ("Tuesday", "TUESDAY"),
    ("WEDNESDAY", "WEDNESDAY"),
    ("THURSDAY", "THURSDAY"),
    ("FRIDAY", "FRIDAY"),
    ("SATURDAY", "SATURDAY"),
    ("SUNDAY", "SUNDAY"),
    ("ALL DAY", "ALL DAY")
)
station_id = models.AutoField(primary_key=True)
state = models.ForeignKey(State, on_delete=models.CASCADE)
city = models.ForeignKey(City, on_delete=models.CASCADE)
area = models.ForeignKey(Area, on_delete=models.CASCADE)
user = models.ForeignKey(User, on_delete=models.CASCADE)
station_name = models.CharField(max_length=50)
station_address = models.CharField(max_length=255)
connectors = models.CharField(max_length=50)
status = models.CharField(max_length=20, choices=STAUTUS_CHOICE, default="ACTIVE")
start_time = models.TimeField(null=True)
end_time = models.TimeField(null=True)
open_day = models.CharField(max_length=20, choices=DAY_CHOICE, default="ALL DAY")
# give_feedback = models.CharField(max_length=255, null=True)
deleted = models.IntegerField(default=0, unique=False)

add_station.html #

<form method="post" action="" novalidate>
    {% csrf_token %}
    <div class="form-row">
        <div class="form-group col-md-12 mb-0">
            {{ form.station_name|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-12 mb-0">
            {{ form.station_address|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.connectors|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.status|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.start_time|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.end_time|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.open_day|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.state|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.city|as_crispy_field }}
        </div>
        
        <div class="form-group col-md-6 mb-0">
            {{ form.area|as_crispy_field }}
        </div>
        
        <button type="submit" class="w-full rounded-full bg-red-gradient p-3 text-white font-bold hover:ring">Add Station</button>
    </div>
</form> 

问题解决 #

1. 处理user_type_id cannot be null错误 #

这个错误和Station模型的user外键无关，是当前登录的User实例本身缺少必填的user_type字段值导致的：

• 检查User模型的user_type字段，若不需要强制关联，添加null=True, blank=True参数
• 确保当前登录用户已经在后台设置了对应的user_type值

2. 解决表单提交后清空刷新的问题 #

这是表单验证失败但未显示错误提示导致的，按以下步骤修改：

• 从视图的fields中移除user字段，因为已经在form_valid中自动绑定当前用户，无需在表单中展示
• 在模板表单顶部添加错误提示代码，以便看到验证失败原因：

  {% if form.errors %}
      <div class="alert alert-danger">
          {% for field in form %}
              {% for error in field.errors %}
                  <p>{{ field.label }}: {{ error }}</p>
              {% endfor %}
          {% endfor %}
          {% for error in form.non_field_errors %}
              <p>{{ error }}</p>
          {% endfor %}
      </div>
  {% endif %}
  

• 检查state、city、area外键字段是否有可用数据，提交表单时必须选择有效值

修改后的视图代码：

class StationCreateView(LoginRequiredMixin, CreateView):
    model = Station
    fields = ('station_name', 'station_address','connectors','status', 'start_time','end_time','open_day', 
                'state', 'city', 'area')
    template_name = 'owner/add_station.html'

    def form_valid(self, form):
        form.instance.user = self.request.user
        return super().form_valid(form)

内容的提问来源于stack exchange，提问作者Kukadiya Keval