How to pull numbers that are the same

[SteveLord]

NEWB ALERT!


Okay, so we run Sybase Anwhere 8 here along with InfoMaker 6. I have a database of doctors and want to run a query to check out if any have the same license number as another.

What is a SQL command that would detect duplicate numbers?

I am learning this as I go. Thanks.

 

[PDreyer]

Create a unique index on license number to prevent duplicates

To find already existing duplicates
select license, count(*)
from doctors
group by license
having count(*)>1