与外键相关，Django

问题描述

我是 Django 的新用户，我有两个模型，一个是部门，另一个是员工。我需要链接这两个表，以便我能够查看表中每个部门下的详细信息。但我收到错误消息“NOT NULL 约束失败：pom_employee.department_id”。我没有在这个项目中使用表单。请帮帮我

In models.py

class Department(models.Model):
    name = models.CharField(max_length=50)

    def __str__(self):
        return self.name

class Employee(models.Model):
    name = models.CharField(max_length=124)
    age = models.IntegerField()
    department = models.ForeignKey(Department,on_delete=models.CASCADE,null=True)

    def __str__(self):
        return self.name

In views.py

def empdata(request):
    if request.method == "POST":
        name = request.POST.get('empname',False)
        age = request.POST.get('empage',False)

        try:
            Employee.objects.create(name=name,age=age)

            return redirect('/showemp')
        except Employee.DoesNotExist:
            print("I am in except")
            Employee.objects.get(name=name,age=age).save()
    return render(request,'showempdetails.html')

解决方法

你可以试试这个。如果它给出任何错误，请告诉我它说的是什么：

class Department(models.Model):
    name = models.CharField(max_length=50)

    def __str__(self):
        return self.name

class Employee(models.Model):
    name = models.CharField(max_length=124)
    age = models.IntegerField()
    department = models.ForeignKey(Department,on_delete=models.CASCADE,null=True,blank=True)

    def __str__(self):
        return self.name


views.py

    def empdata(request):
        if request.method == "POST":
            name = request.POST.get('empname')
            age = request.POST.get('empage')
            
            try:
                emp = Employee(name=name,age=age)
                emp.save()
                return redirect('/showemp')
            except Employee.DoesNotExist:
                print("I am in except")
        return render(request,'showempdetails.html')

您可以删除旧的迁移并重新运行新的迁移。

,

如果你想要空白，那么不要使用级联

    department = models.ForeignKey(Department,blank=True)

改变

    department = models.ForeignKey(Department,blank=True)