Question

From this table

D_value
-------
A 
B 
B 
C 
C 
C 

To display count D_Value into this table

A | B | C
---------
1 | 2 | 3

Answer 1

To get a single row, use this.

SELECT
   COUNT(CASE WHEN D_Value = 'A' THEN 1 END) AS A,
   COUNT(CASE WHEN D_Value = 'B' THEN 1 END) AS B,
   COUNT(CASE WHEN D_Value = 'C' THEN 1 END) AS C
FROM
   MyTable

This works for a finite and fixed number of values to count

If you do not know how many different values, then you need to do a simple aggregate and make a single row in the client code.

SELECT D_value, COUNT(*) FROM MyTable GROUP BY D_value;

However, this won’t give zero counts for values that do not exist. So you’d need a lookup table and LEFT JOIN. I won’t go there yet…