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Urgent Help required!!

 
Sajee Joseph
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Posts: 200
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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
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Posts: 1879
MySQL Database Suse
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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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