A single query to get the sum of count from different tables in MySQL?

To get the sum of count from different tables, use UNION ALL. Let us first create a table −

mysql> create table DemoTable1
-> (
-> Id int,
-> Name varchar(30)
-> );
Query OK, 0 rows affected (1.55 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1 values(10,'Chris Brown');
Query OK, 1 row affected (0.83 sec)
mysql> insert into DemoTable1 values(20,'David Miller');
Query OK, 1 row affected (0.50 sec)
mysql> insert into DemoTable1 values(30,'John Adam');
Query OK, 1 row affected (0.83 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable1;

Output

+------+--------------+
| Id   | Name         |
+------+--------------+
| 10   | Chris Brown  |
| 20   | David Miller |
| 30   | John Adam    |
+------+--------------+
3 rows in set (0.00 sec)

Following is the query to create second table −

mysql> create table DemoTable2
-> (
-> Amount int
-> );
Query OK, 0 rows affected (1.17 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable2 values(100);
Query OK, 1 row affected (0.30 sec)
mysql> insert into DemoTable2 values(200);
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable2 values(300);
Query OK, 1 row affected (0.54 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable2;

Output

+--------+
| Amount |
+--------+
| 100    |
| 200    |
| 300    |
+--------+
3 rows in set (0.00 sec)

Here is how to get sum of count from different tables in a single query −

mysql> select sum(AllCount) AS Total_Count
-> from
-> (
-> (select count(*) AS AllCount from DemoTable1)
-> union all
-> (select count(*) AS AllCount from DemoTable2)
-> )t;

Output

+-------------+
| Total_Count |
+-------------+
| 6           |
+-------------+
1 row in set (0.03 sec)