How to use COUNT() and IF() in a single MySQL query?

Let us first create a table −

mysql> create table DemoTable
(
   isValidUser boolean
);
Query OK, 0 rows affected (0.70 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(true);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable values(false);
Query OK, 1 row affected (0.07 sec)
mysql> insert into DemoTable values(false);
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values(true);
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values(true);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable values(true);
Query OK, 1 row affected (0.28 sec)
mysql> insert into DemoTable values(false);
Query OK, 1 row affected (0.09 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+-------------+
| isValidUser |
+-------------+
|           1 |
|           0 |
|           0 |
|           1 |
|           1 |
|           1 |
|           0 |
+-------------+
7 rows in set (0.00 sec)

Let us now see the query to use COUNT() and IF() in a single MySQL query −

mysql> select count(if(isValidUser=1,1,NULL)) AS TOTAL_NUMBER_OF_ONE from DemoTable;

This will produce the following output −

+---------------------+
| TOTAL_NUMBER_OF_ONE |
+---------------------+
|                   4 |
+---------------------+
1 row in set (0.06 sec)