How to get the set of rows which are having same cut-off marks?

Question

Name      Age      Cut-off
--------------------------
Ram       22        89.50
Ganesh    22        66.00
Sam       22        92.00
Albert    22        89.50
Kannan    22        65.45   
John      22        66.00

In above table Ram and Albert as well as Ganesh and John having same cut-off value. How can i get all these rows?

Answer 1

SELECT  a.*
FROM    tableName a
        INNER JOIN
        (
            SELECT `Cut-off`, COUNT(*) totalCOunt
            FROM    tableName
            GROUP   BY `Cut-off`
            HAVING  COUNT(*) > 1
        ) b ON a.`Cut-off` = b.`Cut-off`

for faster performance, add an INDEX on column Cut-off

• SQLFiddle Demo

Answer 2

Here is one way to do it:

select *
from t
where exists (select 1 from t t2 where t2.cutoff = t.cutoff and t2.name <> t.name)