How to find string count of a particular id in a column using a MySQL query?

For this, use the CHAR_LENGTH() function in MySQL. Let us first create a table −

mysql> create table DemoTable
   (
   Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   Subject longtext
   );
Query OK, 0 rows affected (1.17 sec)

Now you can insert some records in the table using insert command −

mysql> insert into DemoTable(Subject) values('MySQL,MongoDB');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable(Subject) values('MySQL,MongoDB');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable(Subject) values('MongoDB');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable(Subject) values('MySQL');
Query OK, 1 row affected (0.15 sec)
Display all records from the table using select statement :
mysql> select *from DemoTable;

Output

+----+---------------+
| Id | Subject       |
+----+---------------+
| 1  | MySQL,MongoDB |
| 2  | MySQL,MongoDB |
| 3  | MongoDB       |
| 4  | MySQL         |
+----+---------------+
4 rows in set (0.00 sec)

Following is the query to find string count with a MySQL query of a particular id in a column. We are checking for id 1 here −

mysql> select Id,char_length(Subject) - char_length(REPLACE((Subject), ',', ''))+1 
   AS FreqSubject from DemoTable WHERE char_length(Subject) > 0 AND Id = 1;

Output

+----+-------------+
| Id | FreqSubject |
+----+-------------+
| 1  | 2           |
+----+-------------+
1 row in set (0.02 sec)

Arjun Thakur

Published on 13-Jun-2019 07:59:22