BINARY and varBINARY

BINARY(n) ,varBINARY(n)： N代表字节数

utf8:

mysql> CREATE TABLE t (c BINARY(3));
Query OK, 0 rows affected (0.04 sec)

mysql> INSERT INTO t SET c = 'a';
Query OK, 1 row affected (0.19 sec)

mysql> SELECT HEX(c), c = 'a', c = 'a' from t;
+--------+---------+-------------+
| HEX(c) | c = 'a' | c = 'a' |
+--------+---------+-------------+
| 610000 | 0 　　　　| 　　1 　　　　|
+--------+---------+-------------+
1 row in set (0.01 sec)





mysql> CREATE TABLE tr (c varBINARY(3));
Query OK, 0 rows affected (0.04 sec)

mysql> INSERT INTO tr SET c = 'a';
Query OK, 1 row affected (0.00 sec)

mysql> SELECT HEX(c), c = 'a', c = 'a' from tr;
+--------+---------+-------------+
| HEX(c) | c = 'a' | c = 'a' |
+--------+---------+-------------+
| 61 　　 | 1 　　　　| 　　0 　　　　|
+--------+---------+-------------+
1 row in set (0.01 sec)