Re: Unique value

> sultan wrote:
>
> Hi friends,
>
>
> I have a tables A and B
>
> DESC A
> ------------
> ID NUMBER
> NAME VARHAR2(10)
>
> DESC B
> -----------
> ID NUMBER
> SUBNAME VARCHAR2(20);
>
>
>
> In the above table B.ID is the foreign key to A.ID.
>
> How can I create unique value for B.SUBNAME based on A.NAME.
>
> Means , A.NAME has value 'AAAA" and
> B.SUBNAME has values 'BBBB', 'CCCC';
> when I insert value again in B.SUBNAME as 'BBBB' it
> should not agree for the combination value of A.NAME('AAAA'),
> but 'BBBB' can agree when I enter value for A.NAME
> other than 'AAAA'
>
> Please give some ideas,
>
> Thanks in advance
>
> syed.

Unique index on (id, subname), that's what concatenated indices are for.

-- 
Regards,

Stephane Faroult
Oriole Software
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Stephane Faroult
  INET: sfaroult_at_oriole.com

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