How to remove unconvertable characters to ASCII with SELECT in MySQL?

Let us first create a table −

mysql> create table DemoTable
(
   Value varchar(100)
);
Query OK, 0 rows affected (0.57 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('€986');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable values('§97');
Query OK, 1 row affected (0.15 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+--------+
| Value  |
+--------+
| €986   |
| §97
+--------+
2 rows in set (0.00 sec)

Following is the query to remove unconvertable characters to ASCII −

mysql> select replace(convert(Value using ascii),'?','') from DemoTable;

This will produce the following output −

+--------------------------------------------+
| replace(convert(Value using ascii),'?','') |
+--------------------------------------------+
| 986                                        |
| 97                                         |
+--------------------------------------------+
2 rows in set (0.00 sec)