当我需要在模型中使用当前用户时。假设我有一个带有 current_user 字段的模型,例如:
class MyModel(models.Model):
user = models.ForeignKey(User,on_delete=models.CASCADE,default=None)
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我的理解是可以获取用户:
1)通过导入当前用户:
from django.contrib.auth.models import User
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或者
2)将用户设置为:
from django.contrib.auth import get_user_model
User = get_user_model()
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我明白,如果我没有错,两者都会起作用!!
那么这两种方法之间的主要区别是什么?谢谢
我有两个班级(表),学校和学生之间有关联(外键),当我创建一个新学生时,我希望它自动填写学校字段(这是在学校班级(表)中命名字段的外键)我曾尝试过def get_initial(self):没有运气(它给了我错误)。如果有人可以指出我在做什么错…感谢Models.py:
class School(models.Model):
school_pk = models.AutoField(primary_key=True)
name = models.CharField(max_length=256)
principal = models.CharField(max_length=256)
location = models.CharField(max_length=256)
def __str__(self):
return str(self.name)
def get_absolute_url(self):
return reverse("basic_app:school_detail",kwargs={'school_pk':self.school_pk})
class Student(models.Model):
student_pk = models.AutoField(primary_key=True)
name = models.CharField(max_length=256)
age = models.PositiveIntegerField()
school = models.ForeignKey(School,related_name='students',on_delete=models.CASCADE,default=None)
def __str__(self):
return self.name
def get_absolute_url(self):
return reverse("basic_app:student_detail",kwargs={'student_pk':self.student_pk,'school':self.school})
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views.py:
class StudentCreateView(CreateView):
fields = ("name","age","school")
model = models.Student
template_name = 'basic_app/student_form.html'
pk_url_kwarg = 'student_pk'
slug_url_kwarg='school'
def get_initial(self):
school = get_object_or_404(models.School, school_pk=self.kwargs.get('school_pk'))
return {
'school':school,
}
Run Code Online (Sandbox Code Playgroud) 我正在尝试为字典(任何数据类型)创建一个通用函数.我调用函数时遇到此错误:
错误:无法将类型'[Int:String]'的值转换为预期的参数类型'[_:_]'wprintgeneric(inp:w)^
我的代码如下:
var w=[1:"wisam",2:"khlaid",3:"abd"] //dictionary
func wprintgeneric<T>(inp:[T:T]){
for (i,j) in inp{print(i,j)}
}
wprintgeneric(inp: w)
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