MySQL query to remove numbers after hyphen in a VARCHAR string with numbers

For this, use SUBSTRING_INDEX(). Let us first create a table −

mysql> create table DemoTable2040
   -> (
   -> StudentCode varchar(20)
   -> );
Query OK, 0 rows affected (0.85 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable2040 values('John-232');
Query OK, 1 row affected (0.13 sec)

mysql> insert into DemoTable2040 values('Carol-901');
Query OK, 1 row affected (0.11 sec)

mysql> insert into DemoTable2040 values('David-987');
Query OK, 1 row affected (0.21 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable2040;

This will produce the following output −

+-------------+
| StudentCode |
+-------------+
| John-232    |
| Carol-901   |
| David-987   |
+-------------+
3 rows in set (0.00 sec)

Here is the query to remove numbers after hyphen −

mysql> update DemoTable2040
   -> set StudentCode=substring_index(StudentCode,'-',1);
Query OK, 3 rows affected (0.21 sec)
Rows matched: 3 Changed: 3 Warnings: 0

Let us check the table records once again −

mysql> select *from DemoTable2040;

This will produce the following output −

+-------------+
| StudentCode |
+-------------+
| John        |
| Carol       |
| David       |
+-------------+
3 rows in set (0.00 sec)