I have a table which contains two columns namely

attribute(c)
Accountno (n)

The data is as follows

Attribute				Accountno

GOOD					12345256
GOOD					12345256
GOOD					12345256
GOOD					67569856
FAIR					65957514
FAIR					65957514
AVG					99628522
AVG					65957514
AVG					12345256

In the above table you could see that the account number 12345256 has repeated attribute for GOOD for 3 times. Similarly account Number has FAIR for two times.

For my program, I need to have an attribute for only one time.
So I need an SQL that could trace the repeated values of an attribute if the account number is same.