标签：classlist orm div file 技术 int google turn ret
models代码如下：
class Course(models.Model):
name = models.CharField(unique=True, max_length=64)
price = models.PositiveIntegerField(default=19800)
outline = models.TextField()
def __str__(self):
return "%s" % self.name
class Meta:
verbose_name_plural = "课程信息表"
verbose_name = "课程信息表"
class ClassList(models.Model):
course = models.ForeignKey("Course")
semester = models.PositiveIntegerField(verbose_name="学期")
class_type_choice = ((0, ‘脱产‘),
(1, ‘周末‘),
(2, ‘网络‘),
)
branch = models.ForeignKey("Branch")
class_type = models.PositiveIntegerField(choices=class_type_choice)
teachers = models.ManyToManyField("UserProfile")
start_date = models.DateField()
end_date = models.DateField()
def __str__(self):
return "%s(%s)" % (self.course, self.semester)
class Meta:
verbose_name_plural = "班级信息表"
verbose_name = "班级信息表"
unique_together = ("course", "semester")
两个表关系如上，ClassList表的course是一个外键，关联上面的Course表。
我想在ClassList中定义__str__函数，就像代码中写的。
我是用django的modelform来处理数据并构建web页面。
结果在进入那个由modelform构建的页面时，发生了异常
if rel_obj is None and not self.field.null:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (self.field.model.__name__, self.field.name)
)
else:
return rel_obj
so，就是那个RelatedObjectDoesNotExist，google了很久，发现有个网友说的很好：
https://stackoverflow.com/questions/26270042/how-do-you-catch-this-exception#comment41357708_26270785
class ClassList(models.Model):
course = models.ForeignKey("Course")
semester = models.PositiveIntegerField(verbose_name="学期")
class_type_choice = ((0, ‘脱产‘),
(1, ‘周末‘),
(2, ‘网络‘),
)
branch = models.ForeignKey("Branch")
class_type = models.PositiveIntegerField(choices=class_type_choice)
teachers = models.ManyToManyField("UserProfile")
start_date = models.DateField()
end_date = models.DateField()
def __str__(self):
try:
return "%s(%s)" % (self.course, self.semester)
except Course.DoesNotExist:
return "%s" % self.semester
正如大神网友所说，我抓住了这个异常，随便返回个不是外键的值就好了。
无FUCK说~~~希望能帮到大家。。。
Django models的诡异异常RelatedObjectDoesNotExist
标签：classlist orm div file 技术 int google turn ret
原文地址：http://www.cnblogs.com/yunweiqiang/p/7391259.html
