mysql中文乱码终结

 

mysql中文乱码终结

2008-03-20 13:00

接下来就是创建数据库，名字为sample

然后建立一个table: employee,内容如下（其中应该是email,可是我不小心在建数据库打错了，将错就错了）：
+-------------+------------------+------+-----+---------+----------------+
| Field       | Type             | Null | Key | Default | Extra          |
+-------------+------------------+------+-----+---------+----------------+
| employee_id | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| last_name   | varchar(20)      | YES |     | NULL    |                |
| first_name | varchar(20)      | YES |     | NULL    |                |
| birth       | date             | YES |     | NULL    |                |
| sex         | enum('m','f')    | YES |     | m       |                |
| emmail      | varchar(39)      | YES |     | NULL    |                |
+-------------+------------------+------+-----+---------+----------------+

如果只是这样的话，就会出现这样的错误：报告的错误是：sqle=com.mysql.jdbc.MysqlDataTruncation:
Data truncation: Data too long
for column 'last_name' at row 1 从 employee！
有的情况是：| name         |
+-------------+
| ??           |
| 54243654321 |
| ??           |
| ??           |
+-------------+出现问号！

前面我们已经说过了，mysql默认的编码是latin1,不是我们所需要的gbk,所以我们要修改成为utf8，因为若要正确显示中文繁、简、日文、韩文 使用utf8，修改方法如下：
ALTER DATABASE sample ####这里修改整个数据库的编码
       CHARACTER SET utf8
       DEFAULT CHARACTER SET utf8
       COLLATE utf8_general_ci
       DEFAULT COLLATE utf8_general_ci;

当然了，你也可在在建数据库的时候指定编码，比如：

CREATE DATABASE sample

       CHARACTER SET utf8
       DEFAULT CHARACTER SET utf8
       COLLATE utf8_general_ci
       DEFAULT COLLATE utf8_general_ci ;

接下来要做的是打开mysql所在的目录下的my.nin

在[mysqld]段加入一下代码改成：


default-character-set=utf8

 启动mysql，输入：

执行下列语句，看看结果是不是下面的：
mysql> show variables like '%character%';
+--------------------------+-------------------------------------------+
| Variable_name            | Value                                     |
+--------------------------+-------------------------------------------+
| character_set_client     | latin1                                    |
| character_set_connection | latin1                                    |
| character_set_database   | utf8                                      |
| character_set_results    | latin1                                    |
| character_set_server     | utf8                                                                         
| character_set_system     | utf8                                      |
| character_sets_dir       | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+

mysql> show variables like '%collation%';
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database   | utf8_general_ci   |
| collation_server     | utf8_general_ci   |
+----------------------+-------------------+

接着你再看看执行那个Mysql.html 文件：这回你可以看到的是
mysql> select * from employee;
+-------------+-----------+------------+------------+------+--------------+
| employee_id | last_name | first_name | birth      | sex | emmail       |
+-------------+-----------+------------+------------+------+--------------+
|          12 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
|          13 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
|          14 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
|          15 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
|          16 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
|          17 | ?         | ??         | 1978-12-11 | f    | [e-mail] |
+-------------+-----------+------------+------------+------+--------------+

这当然不是我们希望看到的，我们需要的现实完美正确的中文：
我们还有最后一招：
mysql> SET NAMES 'gbk' ;
Query OK, 0 rows affected (0.00 sec)
因为我们需要的是gbk.
看看mysql中的character设置情况：
mysql> SHOW VARIABLES LIKE '%character%' ;
+--------------------------+-------------------------------------------+
| Variable_name            | Value                                     |
+--------------------------+-------------------------------------------+
| character_set_client     | gbk                                       |
| character_set_connection | gbk                                       |
| character_set_database   | utf8                                      |
| character_set_results    | gbk                                       |
| character_set_server     | utf8                                      |
| character_set_system     | utf8                                      |
| character_sets_dir       | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+
7 rows in set (0.00 sec)

mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-----------------+
| Variable_name        | Value           |
+----------------------+-----------------+
| collation_connection | gbk_chinese_ci |
| collation_database   | utf8_general_ci |
| collation_server     | utf8_general_ci |
+----------------------+-----------------+

这个才是我们最终需要的。
在来查看执行完Mysql_jstl.jsp后的数据库中的结果：
mysql> select * from employee;
|          14 | 王        | 彭给       | 1978-12-11 | f    | [e-mail] |
|          15 | 田        | 王光       | 1978-12-11 | f    | [e-mail] |
|          16 | 息        | 存入       | 1978-12-11 | f    | [e-mail] |
|          17 | 往        | 小杯       | 1978-12-11 | f    | [e-mail] |
+-------------+-----------+------------+------------+------+--------------+

可以高兴得看到了中文，并且在浏览器中也显示正确。

但是仅仅这样的话，当你重新启动mysql的时候
所有的设置又失效了。
mysql> show variables like '%character%';
+--------------------------+-------------------------------------------+
| Variable_name            | Value                                     |
+--------------------------+-------------------------------------------+
| character_set_client     | latin1                                    |
| character_set_connection | latin1                                    |
| character_set_database   | utf8                                      |
| character_set_results    | latin1                                    |
| character_set_server     | utf8                                      |
| character_set_system     | utf8                                      |
| character_sets_dir       | C:/MySQL/MySQL Server 5.0/share/charsets/ |
+--------------------------+-------------------------------------------+

mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database   | utf8_general_ci   |
| collation_server     | utf8_general_ci   |
+----------------------+-------------------+
重新读取又出现乱码：
mysql> select * from employee;
+-------------+-----------+------------+------------+--
| employee_id | last_name | first_name | birth      | s
+-------------+-----------+------------+------------+--
|          12 | ?         | ??         | 1978-12-11 | f
|          13 | ?         | ??         | 1978-12-11 | f
|          14 | ?         | ??         | 1978-12-11 | f
|          15 | ?         | ??         | 1978-12-11 | f
|          16 | ?         | ??         | 1978-12-11 | f
|          17 | ?         | ??         | 1978-12-11 | f
+-------------+-----------+------------+------------+--
所以我们需要在客户端设置系统能识别中文的编码gbk并没有保存到my.ini文件中。所以要修改my.ini文件

在[mysql]段加入一下代码改成：default-character-set=gbk 这样设置就得到保存了。
重启就可以了。
mysql> show variables like '%character%';
+--------------------------+----------------
| Variable_name            | Value
+--------------------------+----------------
| character_set_client     | gbk
| character_set_connection | gbk
| character_set_database   | utf8
| character_set_results    | gbk
| character_set_server     | utf8
| character_set_system     | utf8
| character_sets_dir       | C:/MySQL/MySQL
+--------------------------+----------------
mysql> SHOW VARIABLES LIKE '%collation%' ;
+----------------------+-----------------+
| Variable_name        | Value           |
+----------------------+-----------------+
| collation_connection | gbk_chinese_ci  |
| collation_database   | utf8_general_ci |
| collation_server     | utf8_general_ci |
+----------------------+-----------------+