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Urgent Help required!!

Sajee Joseph
Ranch Hand

Joined: Jan 17, 2001
Posts: 200
Hi all,
Im relatively new to database and that too on Oracle. I have a problem in designing a table. Let this table be TableA. It has some fields. Let the combinational key in this table be a, b, c.
The field 'c' is of Integer type. My problem is this: I dont want the developer to gerenate the key 'c'. The different combinations of a, b, c are : a1,b1,1
a1,b1,2
a1,b1,3
a2,b1,1
a2,b1,2
a1,b2,1
a1,b2,2
etc.....
From this series you can see that whenever the a,b combination is the same, the c value will be different and consecutive (eg: first 3 rows).
How ever i can have the same c value, when the a, b combination is different. That is if i insert another row with a = a1 and b = b1, then the c value should be 4.

I hope u got my question.
How can i achieve this??
Someone told me i can use triggers
Please help me out
Kindest Regards
Saj
Jamie Robertson
Ranch Hand

Joined: Jul 09, 2001
Posts: 1879

you need to create a composite primary key. This is very common, and if you refer to any Oracle manuals on how to create a table, they will show you how to create a primary key on the 3 columns.
 
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subject: Urgent Help required!!