MySQL query to sum 3 different values in a column displaying total of each value in result set?

For this, you can use a CASE statement. Let us first create a table −

mysql> create table DemoTable
(
   ProductName varchar(100),
   ProductRating ENUM('1','2','3')
);
Query OK, 0 rows affected (0.50 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('Product-1',3);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable values('Product-2',1);
Query OK, 1 row affected (0.08 sec)
mysql> insert into DemoTable values('Product-3',2);
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable values('Product-1',2);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values('Product-3',3);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values('Product-2',2);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values('Product-3',3);
Query OK, 1 row affected (0.10 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-------------+---------------+
| ProductName | ProductRating |
+-------------+---------------+
| Product-1   | 3             |
| Product-2   | 1             |
| Product-3   | 2             |
| Product-1   | 2             |
| Product-3   | 3             |
| Product-2   | 2             |
| Product-3   | 3             |
+-------------+---------------+
7 rows in set (0.00 sec)

Here is the query to sum 3 different values in a column displaying a total of each value in the result set. We are adding on the basis of Product Rating −

mysql> select ProductName,
   sum( case when ProductRating=3 then 1 else 0 end ) as Product_3_Rating,
   sum( case when ProductRating=2 then 1 else 0 end ) as Product_2_Rating,
   sum( case when ProductRating=1 then 1 else 0 end ) as Product_1_Rating
   from DemoTable
   group by ProductName;

This will produce the following output −

+-------------+------------------+------------------+------------------+
| ProductName | Product_3_Rating | Product_2_Rating | Product_1_Rating |
+-------------+------------------+------------------+------------------+
| Product-1   |                1 |                1 |                0 |
| Product-2   |                0 |                1 |                1 |
| Product-3   |                2 |                1 |                0 |
+-------------+------------------+------------------+------------------+
3 rows in set (0.00 sec)