[Answered ]-Proper construction of Django Model

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1👍

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Since each exercise has one or more properties that you want to measure, you should extract those properties out, so you end up with three main models.

class Metric(models.Model):
   name = models.CharField(max_length=20)
   description = models.TextField(null=True, blank=True)
   measured_in = models.CharField(max_length=20, null=True, blank=True)
   # other fields

class Measurement(models.Model):
   metric = models.ForeignKey(Metric)
   value = models.CharField(max_length=20, null=True, blank=True)
   workout_date = models.DateField(auto_now=True)

class Workout(models.Model):
   # common attributes for each workout
   name = models.CharField(max_length=200)
   notes = models.TextField()
   metrics = models.ManyToManyField(Measurement)

You add various metrics (things you measure) to Metric. For each workout, you identify which metric you want to track, by adding creating a new Measurement. Finally, you associate it to each workout when you create it.

Here is a sample:

reps = Metric.objects.create(name='Reps')
my_reps = Measurement.objects.create(metric=reps,value=10)
w = Workout(name="Weights")
w.metrics.add(my_reps)
w.save()
👤Burhan Khalid

1👍

This is exactly what inheritance is made for. Create a generic Workout type, and then subclass it with the types of workouts. With the unique/specific attributes on the subclasses.

class Workout(models.Model):
    date = models.DateTimeField("Date", blank=True, default=datetime.now)
    notes = models.TextField("Notes", blank=True)

class Jog(Workout):
    distance = models.DecimalField("Distance (Miles)", max_digits=4, decimal_places=2, blank = True, null=True)
    time = models.DecimalField("Time (Minutes)", max_digits=4, decimal_places=2, blank = True, null=True)

class Weightlifting(Workout):
    reps = models.IntegerField("Repetitions", blank = True, null=True)
    sets = models.DecimalField("Sets", max_digits=2, decimal_places=1, blank = True, null=True)
    weight = models.IntegerField("Weight", blank=True, null=True)

And so on. If you don’t need to use the generic Workout type anywhere, you can make it an abstract model.

👤Chris Pratt

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