Suppose our tablename is masterorder with column orderid for which we are goin to find duplicate records.
SELECT orderid, COUNT(*) TotalCount
GROUP BY orderid
HAVING COUNT(*) > 1
U might have come across a situation like there are number of duplicated records in a table.
Now Its Ur duty to remove duplicacy of data from the table, So the first step would be to find out duplicate records against each column.