I'm making a small training program, and I have various exercises such
as:
biking, strength training etc. Some of the fields for these different
activities
will be the same, like heart rate, duration, time, but some will not
such as distance.

Since the exercises are different, my first thought was to make a
table for each exercise, as this seems to be the nicest way to order
things.

Exercise table:
UserID (PK)
ExerciseID (Auto inc)
ExerciseType (enum to bike, aerobic)
Timestamp
Duration
HR (ref to HR table)

Bike table:
ExerciseID (Foreign key)
Distance
MaxSpeed
Route

Aerobic:
ExerciseID (Foreign key)
Program

What I'm not sure about, is the reference to another table from the
exercise table by using the ExerciseType.

I'm new to database design, so this might a good solution, I'm just
not sure about it. So please let me know what you think about the
design.

koger wrote:
google for "sub super type" in comp.databases, and I think you will find
some examples.

With your design each user can have only one exercise, is that your
intention?


/Lennart