完美解决MySQL中文乱码

时间 2019-11-11

标签完美解决 mysql 中文乱码栏目 MySQL 繁體版

原文原文链接

方法一： http://www.jz123.cn/text/1638253.html

解决MySQL中文乱码的问题php

看到从数据库中取出的数据所有是“？？？？？”，太让人郁闷了。html

网上有不少方法来解决这个问题，能够分为二种，1是修改my.ini配置文件，若是是在网上的空间的话，咱们通常没有权限去修改这个文件。java

我推荐使用使用第二种方法，在数据库链接过程当中，设定字符编码。mysql

以下所示：（加粗部分）sql

@ $db_link=mysql_connect('localhost','user','pass');
MySQL_query("SET NAMES 'utf8'");
mysql_select_db('databasename',$db_link);数据库

方法二：转自http://blog.chinaunix.net/space.php?uid=9195812&do=blog&id=2006339浏览器

为了说的明白一些，我觉个例子：
很简单，就是从html中接受两个输入，而后由jsp处理写到mysql且从数据库返回这个结果显示出来。
Mysql_jstl.html

jsp

<html> <head>   <title>CH14 - Mysql_jstl.html</title> <meta http-equiv="Content-Type" content="text/html; charset= GB2312"> </head> <body> <h2>将信息存入 Mysql 中 - 使用 JSTL 写法</h2> <form name="form" action="Mysql_jstl.jsp" method="post" >   <p>姓：<input name="last_name" type="text" id="last_name"></p>   <p>名：<input name="first_name" type="text" id="first_name"></p>   <p>     <input type="submit" value="传送">     <input type="reset" value="取消">   </p> </form> </body> </html>post

Mysql_jstl.jsp
<%@ page contentType="text/html;charset=GB2312" %> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %> <%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %> <html> <head>   <title>CH14 - Mysql_jstl.jsp</title> </head> <body> <h2>将信息存入 Mysql 中 - 使用 JSTL 写法</h2> <fmt:requestEncoding value="GB2312" /> <c:set var="birth" value="1978/12/11" /> <c:set var="sex" value="F" /> <c:set var="email" value="aaa@asdf.com" /> <sql:setDataSource driver="com.mysql.jdbc.Driver"          url="jdbc:mysql://localhost:3306/sample?useUnicode=true&characterEncoding=UTF-8"          user="root"          password="44444" /> <sql:update>   INSERT INTO employee(employee_id, last_name, first_name, birth,sex, emmail)   VALUES ( ? , ? , ? , ? , ? , ? )      <sql:param value="${employee_id}" />   <sql:param value="${param.last_name}" />   <sql:param value="${param.first_name}" />   <sql:param value="${birth}" />   <sql:param value="${sex}" />   <sql:param value="${email}" /> </sql:update> <sql:query var="result">   SELECT * FROM employee </sql:query> 从 employee 取出全部新增的姓名：<br> <c:forEach items="${result.rows}" var="row" > 新增姓名：<c:out value="${row.last_name}" />      <c:out value="${row.first_name}" /><br> </c:forEach> </body> </html>ui

接下来就是建立数据库，名字为sample

而后创建一个table: employee,内容以下（其中应该是email,但是我不当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    |                |
+-------------+------------------+------+-----+---------+----------------+

若是只是这样的话，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 .并且select last_name from employee.来看也出现了以下的状况：

| last_name        |
+-------------+
| ??          |
| 54243654321 |
| ??          |
| ??          |
+-------------+

出现问号！

前面咱们已经说过了，mysql默认的编码是latin1,不是咱们所须要的gbk,因此咱们要修改为为utf8，由于若要正确显示中文繁、简、日文、韩文使用utf8，修改方法以下：
  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;

固然了，你也可在在建数据库的时候指定编码，好比：

CREATE DATABASE sample

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

接下来要作的是打开mysql所在的目录下的my.nin
在[mysqld]段加入一下代码改为： default-character-set=utf8 启动mysql，输入： 执行下列语句，看看结果是否是下面的： 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：这回你能够看到的是
mysql> select * from employee;
+-------------+-----------+------------+------------+------+--------------+
| employee_id | last_name | first_name | birth      | sex | emmail       |
+-------------+-----------+------------+------------+------+--------------+
|          12 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
|          13 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
|          14 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
|          15 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
|          16 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
|          17 | ?         | ??         | 1978-12-11 | f    | aaa@asdf.com |
+-------------+-----------+------------+------------+------+--------------+

这固然不是咱们但愿看到的，咱们须要的现实完美正确的中文：
咱们还有最后一招：
mysql> SET NAMES 'gbk' ;
Query OK, 0 rows affected (0.00 sec)
由于咱们须要的是gbk.
看看mysql中的character设置状况：
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 |
+----------------------+-----------------+

这个才是咱们最终须要的。
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    | aaa@asdf.com |
|          15 | 田        | 王光       | 1978-12-11 | f    | aaa@asdf.com |
|          16 | 息        | 存入       | 1978-12-11 | f    | aaa@asdf.com |
|          17 | 往        | 小杯       | 1978-12-11 | f    | aaa@asdf.com |
+-------------+-----------+------------+------------+------+--------------+

能够高兴得看到了中文，而且在浏览器中也显示正确。

可是仅仅这样的话，当你从新启动mysql的时候
全部的设置又失效了。
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   |
+----------------------+-------------------+
从新读取又出现乱码：
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
+-------------+-----------+------------+------------+--
因此咱们须要在客户端设置系统能识别中文的编码gbk并无保存到my.ini文件中。因此要修改my.ini文件
在[mysql]段加入一下代码改为：default-character-set=gbk 这样设置就获得保存了。 重启就能够了。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 | +----------------------+-----------------+