Question : Sql query to find duplicate

Hi,
Need to select refno field and Ninumber where I have more than 1 Ninumber from table1

Cheers

Answer : Sql query to find duplicate

small fix, it must be > 1 and not >= 1  (or >= 2 ... )

1: 2: 3: 4: 5:

SELECT refno, Ninumber FROM table_name WHERE Ninumber in ( SELECT Ninumber FROM table_name GROUP BY Ninumber HAVING COUNT(*) > 1)