从模型中给出django继承和m2m链接父母的子查询

Question

在我的模型中，我有锻炼，其中有一个m2m链接到锻炼。我也有WorkoutPlan和LogBook，它们是锻炼类型。 WorkoutPlan是存放理想锻炼的地方。 LogBook是用户存储他们实际完成的锻炼的地方。他们还可以将LogBook链接到WorkoutPlan，以表明实际表现已连接到原始理想计划。

class Exercise(NameDescModel): 
    muscles = models.ManyToManyField(Muscle, blank=True) 
    groups = models.ManyToManyField(Group, blank=True) 
    priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0) 
    frequency = models.IntegerField() 
    time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK) 
    last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now) 

class Workout(NameDescModel): 
    exericises = models.ManyToManyField(Exercise, through='Measurement') 

class WorkoutPlan(Workout): 

    priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0) 
    frequency = models.IntegerField() 
    time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK) 
    time_estimate = models.IntegerField() 
    last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now) 

class LogBook(Workout): 
    workout_date = models.DateField(default=datetime.now) 
    notes = models.TextField(blank=True) 

    workout_plan = models.ForeignKey(WorkoutPlan, blank=True, null=True) 

对于给定的锻炼，我想拉的所有WorkoutPlans的，此次演习是英寸

exercise_list = Exercise.objects.order_by('-last_p_calc_date') 

for exercise in exercise_list: 
    print exercise 
    workout_list = [] 
    for workout in exercise.workout_set.all(): 
     workout_list.append(workout) 
    print list(set(workout_list)) 
    print "" 

我意识到锻炼的名单包括WorkoutPlans和航海日志，因为运动是附加到锻炼，而不是专门针对WorkoutPlans或LogBooks。

我该如何抽取仅附属于WorkoutPlans的锻炼？

Answer 1

我想你已经在这里过度使用了继承。

我想你想把exercises字段放到基本模型中，因为WorkoutPlan和LogBook都有这个字段。但它似乎在现实WorkoutPlan和LogBook是不同类型的东西，而不是Workout的子类型。

也许并不需要的exercises田野上LogBook模式可言，因为它有一个外键WorkoutPlan这似乎是一个明智的地方记录练习......除非你想录制的计划之间的差异和练习实际上执行？

我想这一点，型号：

class Exercise(NameDescModel): 
    muscles = models.ManyToManyField(Muscle, blank=True) 
    groups = models.ManyToManyField(Group, blank=True) 
    priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0) 
    frequency = models.IntegerField() 
    time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK) 
    last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now) 

class WorkoutPlan(Workout): 
    exercises = models.ManyToManyField(Exercise, through='Measurement') 
    priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0) 
    frequency = models.IntegerField() 
    time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK) 
    time_estimate = models.IntegerField() 
    last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now) 

class LogBook(Workout): 
    exercises = models.ManyToManyField(Exercise, through='Measurement') 
    workout_date = models.DateField(default=datetime.now) 
    notes = models.TextField(blank=True) 
    workout_plan = models.ForeignKey(WorkoutPlan, blank=True, null=True) 

然后，您可以查询或者WorkoutPlans或航海日志从练习实例：

exercise_list = Exercise.objects.order_by('-last_p_calc_date') 

for exercise in exercise_list: 
    print exercise 
    workout_list = exercise.workoutplan_set.all() 
    print ""