MySQL query to keep only first 2 characters in column value and delete rest of the characters?

To keep only first two characters and delete rest of the characters, use SUBSTRING().

Let us first create a table −

mysql> create table DemoTable743 (SubjectName varchar(100));
Query OK, 0 rows affected (0.54 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable743 values('MySQL');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable743 values('Java');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable743 values('MongoDB');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable743 values('Python');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable743 values('Data Structure');
Query OK, 1 row affected (0.68 sec)
mysql> insert into DemoTable743 values('Algorithm');
Query OK, 1 row affected (0.12 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable743;

This will produce the following output -

+----------------+
| SubjectName    |
+----------------+
| MySQL          |
| Java           |
| MongoDB        |
| Python         |
| Data Structure |
| Algorithm      |
+----------------+
6 rows in set (0.00 sec)

Following is the query to keep first 2 characters in column value and delete rest of the characters−

mysql> update DemoTable743 set SubjectName=SUBSTRING(SubjectName,1,2);
Query OK, 6 rows affected (0.12 sec)
Rows matched: 6 Changed: 6 Warnings: 0

Let us check the table records once again −

mysql> select *from DemoTable743;

This will produce the following output -

+-------------+
| SubjectName |
+-------------+
| My          |
| Ja          |
| Mo          |
| Py          |
| Da          |
| Al          |
+-------------+
6 rows in set (0.00 sec)