What should I do when I face a challenge of
using a composite primary key.
The situation is that I have a table named
dish.
It has certain parameters/fields which are all
dependent on cell id, but one area of the application has to deal with
the freq a dish can accept or emit.
Now the dish will use 2 major freq , 1800 MHz
and 900 MHz.
What should I do? I created another table with
the following structure:
Dish id
Tilt
Freq.
Tilting of the dish can be for both the
frequencies. The data will be as follows:
Dish1 20 900
Dish1 23 1800
In this case the normalization and database
design is working fine but I cannot make Dish1 the primary key.
Can I make dishid and freq both composite as
the primary key for the table?
Kindly suggest something so I can get out of
this dilemma.
Should I use a sequence?
Thanks a lot for the reply.
This question posed on 17 November 2005
Answer:
You should use a composite key with both the
dishid and freq columns (assuming a dish cannot have more than one
frequency)
