mysql> create table test(ch int, vch varchar(16));
Query OK, 0 rows affected (0.19 sec)

mysql> insert into test (ch, vch)
    -> select 1,'11' union all
    -> select 2,'11            ' union all
    -> select 3,'            11' ;
Query OK, 3 rows affected (0.05 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> select * from test where vch = '11';
+------+----------------+
| ch   | vch            |
+------+----------------+
|    1 | 11             |
|    2 | 11             |
+------+----------------+
2 rows in set (0.00 sec)

mysql> select * from test where vch like '11';
+------+------+
| ch   | vch  |
+------+------+
|    1 | 11   |
+------+------+
1 row in set (0.00 sec)