Question

See the below table:

col1     col2
----     ----
 1    |   a      
 2    |   b    
 3    |   c
 4    |   a
 5    |   d
 6    |   b
 7    |   e

Now I want to show only the non-duplicate records. which means 3,5,7.

How to write a query to get the result?

Answer 1

SELECT col1, col2
FROM table
GROUP BY col2
HAVING COUNT(*) = 1;