How to merge queries in a single MySQL query to get the count of different values in different columns?

Let us first create a table −

mysql> create table DemoTable760 (
   ClientId int,
   ClientId2 int
);
Query OK, 0 rows affected (0.79 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable760 values(100,200);
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable760 values(100,200);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable760 values(300,400);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable760 values(300,400);
Query OK, 1 row affected (0.26 sec)
mysql> insert into DemoTable760 values(100,200);
Query OK, 1 row affected (0.23 sec)
mysql> insert into DemoTable760 values(100,200);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable760 values(400,500);
Query OK, 1 row affected (0.08 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable760;

This will produce the following output -

+----------+-----------+
| ClientId | ClientId2 |
+----------+-----------+
|      100 |       200 |
|      100 |       200 |
|      300 |       400 |
|      300 |       400 |
|      100 |       200 |
|      100 |       200 |
|      400 |       500 |
+----------+-----------+
7 rows in set (0.00 sec)

Following is the query to merge queries in a single query to get the count of different values in different columns −

mysql> select sum(ClientId=100) AS ClientId1,sum(ClientId2=200) AS ClientId2 from DemoTable760;

This will produce the following output -

+-----------+-----------+
| ClientId1 | ClientId2 |
+-----------+-----------+
|         4 |         4 |
+-----------+-----------+
1 row in set (0.00 sec)