我想知道他们在将一个列从IntegerField转换为外键时的最佳程序。这是我的两个模型:
class workout(models.Model):
userid = models.IntegerField()
datesubmitted = models.DateField()
workoutdate = models.DateField();
bodyweight = models.FloatField(null=True);
totalreps = models.IntegerField()
totalweight = models.FloatField()
numsets = models.IntegerField();
numexercises = models.IntegerField()
workoutname = models.CharField(max_length=250)
和第二个:
class exercise(models.Model):
userid = models.IntegerField();
workoutid = models.IntegerField();
exercisename = models.CharField(max_length = 100)
repetitions = models.IntegerField()
weight = models.FloatField()
最后我的django查看代码:
user =User.objects.get(username = request.session['username']) #user
dates = request.GET.getlist('datepickerfilter') # two dates
workout_ids = workout.objects.filter(userid=user.id).filter( workoutdate__gte = dates[0]).filter(workoutdate__lte = dates[1])
all_exercises = exercise.objects.filter(workoutid__in = workout_ids)
我想将练习模型中的“workoutid”列更改为与锻炼模型中的id字段相关的外键。我尝试将更改模型字段更改为:
workoutid = models.ForeignKey(workout);
然后在我的视图中将此order_by语句添加到all_exercises的末尾,即
all_exercises = exercise.objects.filter(workoutid__in = workout_ids).order_by("workoutid__workoutdate")
我得到一个错误说:
(1054, "Unknown column 'tracking_exercise.workoutid_id' in 'field list'")
我认为这是我的模型代码中的一个问题,但我不确定它是否与视图有关。
感谢帮帮!
答案 0 :(得分:1)
您收到错误,因为workout_ids不是ID列表。
对当前问题的快速而简单的解决方法是使用.values_list('id', flat=True)
,如下所示:
workout_ids = workout.objects.filter(userid=user.id).\
filter(workoutdate__gte=dates[0]).\
filter(workoutdate__lte=dates[1]).\
values_list('id', flat=True)
但是,我强烈建议您使用models.ForeignKey
。这是一个让你入门的简单例子:
class Workout:
user = models.ForeignKey(User)
# other fields go here...
class Exercise:
workout = models.ForeignKey(Workout)
# other fields go here...
然后你可以编写查询:
workout_list = Workout.objects.filter(user=request.user)
exercise_list = Exercise.objects.filter(workout__in=workout_list).order_by('workout__workoutdate')