How to implement HAVING LENGTH(field) in MySQL?

Let us first create a table −

mysql> create table DemoTable
(
   Title text
);
Query OK, 0 rows affected (0.39 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('Introduction to MySQL');
Query OK, 1 row affected (0.11 sec)
mysql> insert into DemoTable values('Introduction to Java');
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values('Introduction to SQL');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values('Introduction to Python');
Query OK, 1 row affected (0.10 sec)
mysql> insert into DemoTable values('Introduction to SQL');
Query OK, 1 row affected (0.09 sec)
mysql> insert into DemoTable values('Introduction to Java');
Query OK, 1 row affected (0.13 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+------------------------+
| Title                  |
+------------------------+
| Introduction to MySQL  |
| Introduction to Java   |
| Introduction to SQL    |
| Introduction to Python |
| Introduction to SQL    |
| Introduction to Java   |
+------------------------+
6 rows in set (0.00 sec)

Following is the query to implement HAVING LENGTH(field) in MySQL −

mysql> select *from DemoTable group by length(Title)
   having length(Title) < 21;

This will produce the following output −

+----------------------+
| Title                |
+----------------------+
| Introduction to SQL  |
| Introduction to Java |
+----------------------+
2 rows in set (0.00 sec)