Thomas Kellerer wrote:
> On 26.01.2005 13:25 Ramon wrote:
>
>
>>I have read in this NG that there is a way to to have a
>>uniqueness constraint based on two or more fields.
>>
>>Just to make sure that there are no confusions, I'll
>>provide a very simple example. Suppose I am using SQL*Loader
>>and there is a record with FIRST_NAME='JOHN' and LAST_NAME='SMITH'.
>>
>>Subsequent records with FIRST_NAME='JOHN' will be accepted.
>>Subsequent records with LAST_NAME='SMITH' will be accepted.
>>
>>However, any record containing JOHN SMITH will be rejected for
>>violating the constraint.
>>
>>TIA,
>>
>>-Ramon F Herrera
>>
>
>
> CREATE UNIQUE INDEX ON the_table (first_name, last_name);
>
> should do it, I guess.
>
> Thomas
While your answer is technically correct there is almost not good
reason for ever creating a unique index in Oracle. Unique indexes,
unlike unique constraints are not as well documented in the data
dictionary and can't be deferred.
--
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)
Received on Wed Jan 26 2005 - 12:33:31 CST
