contact mysql column field

1mysql> select * from t;
2+------+-------+
3| id   | data  |
4+------+-------+
5|    1 | max   |
6|    2 | linda |
7|    3 | sam   |
8|    4 | henry |
9+------+-------+
104 rows in set (0.02 sec)
11
12mysql> update t set data=concat(data, 'a');
13Query OK, 4 rows affected (0.01 sec)
14Rows matched: 4  Changed: 4  Warnings: 0
15
16mysql> select * from t;
17+------+--------+
18| id   | data   |
19+------+--------+
20|    1 | maxa   |
21|    2 | lindaa |
22|    3 | sama   |
23|    4 | henrya |
24+------+--------+
254 rows in set (0.00 sec)
26