Re: need sql query to check if a column is unique

On 28 Feb., 11:08, "samir...._at_googlemail.com" <samir...._at_googlemail.com> wrote:
> Hey guys,
>
> I've an table with a column, let's call it employee_id. Do you know an
> sql statement, which can check employee_id, if it has duplicate
> entries ?
>
> regards Samir

select employee_id, count(*) from <table> group by employee_id having count(*) > 1;

How about a UNIQUE constraint ?

regards Received on Wed Feb 28 2007 - 04:36:50 CST