TRIMMIG IN MYSQL

Some time back I got stuck at the point in Mysql task ,I wanted to trip a part of already existing column in table and then insert into other column.

Reference is the column that contains the Reference number e.g. '090216-000016'
RDate is the column is which stores the date of the reference,  and first part of Reference contains the date. So I wanted to trip the Reference number to get the data for RDate column.

Here is how I did it,

mysql> select Reference from RNS  where Reference='090216-000016';
+---------------+
| Reference     |
+---------------+
| 090216-000016 |
+---------------+
1 row in set (0.00 sec)

mysql> select LEFT (Reference,6) from RNS  where Reference='090216-000016';
+--------------------+
| LEFT (Reference,6) |
+--------------------+
| 090216             |
+--------------------+
1 row in set (0.01 sec)

mysql> update RNS set RDATE=LEFT(Reference,6) where Reference='090205-000154';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select Reference,RDATE from RNS  where Reference='090205-000154';
+---------------+------------+
| Reference     | RDATE      |
+---------------+------------+
| 090205-000154 | 2009-02-05 |
+---------------+------------+

Hope it will be useful.