HAVING with GROUP BY in MySQL

To use HAVING with GROUPBY in MySQL, the following is the syntax. Here, we have set a condition under HAVING to get check for maximum value condition −

SELECT yourColumnName FROM yourTableName GROUP BY yourColumnName HAVING MAX(yourColumnName) < yourValue;

Let us see an example by creating a table in MySQL −

mysql> create table WhereAfterGroupDemo -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserProcess int, -> UserThreadId int -> ); Query OK, 0 rows affected (5.74 sec)

Example

Insert some records in the table using insert command. The query is as follows −

mysql> insert into WhereAfterGroupDemo(UserProcess,UserThreadId) values(1211,3); Query OK, 1 row affected (0.10 sec) mysql> insert into WhereAfterGroupDemo(UserProcess,UserThreadId) values(1412,3); Query OK, 1 row affected (0.39 sec) mysql> insert into WhereAfterGroupDemo(UserProcess,UserThreadId) values(1510,4); Query OK, 1 row affected (0.19 sec) mysql> insert into WhereAfterGroupDemo(UserProcess,UserThreadId) values(1511,4); Query OK, 1 row affected (0.31 sec)

Display all records from the table using a select statement. The query is as follows −

mysql> select *from WhereAfterGroupDemo;

Output

+--------+-------------+--------------+ | UserId | UserProcess | UserThreadId | +--------+-------------+--------------+ |      1 | 1211        |            3 | |      2 | 1412        |            3 | |      3 | 1510        |            4 | |      4 | 1511        |            4 | +--------+-------------+--------------+ 4 rows in set (0.00 sec)

The following is the query to use HAVING and GROUP BY and get the UserThreaId with process less than 1510 −

mysql> SELECT UserThreadId FROM WhereAfterGroupDemo GROUP BY UserThreadId HAVING MAX(UserProcess) < 1510;

Output

+--------------+ | UserThreadId | +--------------+ |            3 | +--------------+ 1 row in set (0.00 sec)