SQL 类型的支持：
- PREPARE Syntax
- EXECUTE Syntax
二进制协议的支持：
- COM_STMT_PREPARE
- COM_STMT_EXECUTE
示例：
mysql> select * from test1;
+---+------+
| a | b |
+---+------+
| 5 | 6 |
| 3 | 4 |
| 1 | 2 |
+---+------+
3 rows in set (0.03 sec)
mysql> prepare ff from "select * from test1 where a=?";
Query OK, 0 rows affected (0.00 sec)
Statement prepared
mysql> set @aa=3;
Query OK, 0 rows affected (0.00 sec)
mysql> execute ff using @aa;
+---+------+
| a | b |
+---+------+
| 3 | 4 |
+---+------+
1 row in set (0.06 sec)