以下的文章主要介绍的是Mysql中文问题的实际解决方法,其中主要包括MySql字符集的问题解决,ROR+Mysql5 utf8中正确搭配相关问题的实际解决方案,以下就是文章的具体内容的主要描述,望你浏览之后会有所收获。 『出错』Hibernate对象关系在MySQL4.1中无法正确
以下的文章主要介绍的是Mysql中文问题的实际解决方法,其中主要包括MySql字符集的问题解决,ROR+Mysql5 utf8中正确搭配相关问题的实际解决方案,以下就是文章的具体内容的主要描述,望你浏览之后会有所收获。
『出错』Hibernate对象关系在MySQL4.1中无法正确执行?
推荐圈子: JBoss SEAM
更多相关推荐 阅读过不少关于mysql的编码设置和乱码问题的一些文章,经过再三的调试,终于通过,终于解决了一块心病,终于解了我心头之恨,哈哈哈。现在把它概括如下。
MySQL 4.1的字符集支持(Character Set Support)有两个方面:字符集(Character set)和排序方式(Collation)。对于字符集的支持细化到四个层次: 服务器(server),数据库(database),数据表(table)和连接(connection)。我们最终的目标是使得这四个层次转化会支持Mysql中文的编码,下面以utf8为例。
1. 首先查看系统的字符集和排序方式。如果想查看某个特定的数据库的字符集和排序方式,应该先选定数据库,mysql>use databasename;
<ol class="dp-xml"> <li class="alt"><span><span>mysql</span><span class="tag">></span><span> SHOW VARIABLES LIKE ''character_set_%''; </span></span></li> <li><span>+--------------------------+----------------------------+ </span></li> <li class="alt"><span>| Variable_name | Value | </span></li> <li><span>+--------------------------+----------------------------+ </span></li> <li class="alt"><span>| character_set_client | latin1 | </span></li> <li><span>| character_set_connection | latin1 | </span></li> <li class="alt"><span>| character_set_database | latin1 | </span></li> <li><span>| character_set_results | latin1 | </span></li> <li class="alt"><span>| character_set_server | latin1 | </span></li> <li><span>| character_set_system | utf8 | </span></li> <li class="alt"><span>| character_sets_dir | /usr/share/mysql/charsets/ | </span></li> <li><span>+--------------------------+----------------------------+ </span></li> <li class="alt"><span>7 rows in set (0.00 sec) </span></li> <li> <span>mysql</span><span class="tag">></span><span> SHOW VARIABLES LIKE ''collation_%''; </span> </li> <li class="alt"><span>+----------------------+-------------------+ </span></li> <li><span>| Variable_name | Value | </span></li> <li class="alt"><span>+----------------------+-------------------+ </span></li> <li><span>| collation_connection | latin1_swedish_ci | </span></li> <li class="alt"><span>| collation_database | latin1_swedish_ci | </span></li> <li><span>| collation_server | latin1_swedish_ci | </span></li> <li class="alt"><span>+----------------------+-------------------+ </span></li> <li><span>3 rows in set (0.00 sec) </span></li> </ol>
上面列出的值就是系统的默认值,lanti是不支持Mysql中文的,所以我们把它改成urf8。
下面我们就来修改这四个层次的编码方式:
1 在my.cf文件的[mysqld]段设置:
<ol class="dp-xml"><li class="alt"><span><span class="attribute">default-character-set</span><span>=</span><span class="attribute-value">utf8</span><span> </span></span></li></ol>
这条语句的作用是把character_set_client, character_set_connection_,character_set_results 设定为utf8,包括对应的排列方式的编码。
Character_set_server是系统编码,这个是不用改的。
当然改变character_set_client, character_set_connection_,character_set_results编码方式的另外一种方法是:
<ol class="dp-xml"><li class="alt"><span><span>SET NAMES “UTF8”; </span></span></li></ol>
它的作用相当于:
<ol class="dp-xml"> <li class="alt"><span><span>SET </span><span class="attribute">character_set_client</span><span> = </span><span class="attribute-value">utf8</span><span>; </span></span></li> <li> <span>SET </span><span class="attribute">character_set_results</span><span> = </span><span class="attribute-value">utf8</span><span>; </span> </li> <li class="alt"> <span>SET </span><span class="attribute">character_set_connection</span><span> = </span><span class="attribute-value">utf8</span><span>; </span> </li> </ol>
2. 改变数据库的编码方式
<ol class="dp-xml"><li class="alt"><span><span>alter database databasename character set utf8; </span></span></li></ol>
通过以上的更改数据库的编码工作算是昨晚了,当然除了这个方法还有一个万能个的方法,那就是看着那个不是utf8,你只要把相应的编码改成utf8就可以了。格式如下:SET
<ol class="dp-xml"><li class="alt"><span><span class="attribute">character_set_client</span><span> = </span><span class="attribute-value">utf8</span><span>; </span></span></li></ol>
3. 不管你是web编程还是桌面编程,你的数据库的连接地址url中,一定要后缀:
<ol class="dp-xml"><li class="alt"><span><span>?</span><span class="attribute">useUnicode</span><span>=</span><span class="attribute-value">true</span><span>&</span><span class="attribute">characterEncoding</span><span>=</span><span class="attribute-value">utf</span><span>-8/hibernate?</span><span class="attribute">useUnicode</span><span>=</span><span class="attribute-value">true</span><span>&</span><span class="attribute">characterEncoding</span><span>=</span><span class="attribute-value">utf</span><span>-8 </span></span></li></ol>
当然如果你采用了mysql的管理工具如mysql yog,mysql manager那么你数据库设定也可以在可视化环境下直接设置。当然这也只是限制在database的设定。
以上的相关内容就是对Mysql中文问题解决方案的介绍,望你能有所收获。
【编辑推荐】

MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.

MySQL is an open source relational database management system suitable for data storage, management, query and security. 1. It supports a variety of operating systems and is widely used in Web applications and other fields. 2. Through the client-server architecture and different storage engines, MySQL processes data efficiently. 3. Basic usage includes creating databases and tables, inserting, querying and updating data. 4. Advanced usage involves complex queries and stored procedures. 5. Common errors can be debugged through the EXPLAIN statement. 6. Performance optimization includes the rational use of indexes and optimized query statements.

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.

InnoDB's lock mechanisms include shared locks, exclusive locks, intention locks, record locks, gap locks and next key locks. 1. Shared lock allows transactions to read data without preventing other transactions from reading. 2. Exclusive lock prevents other transactions from reading and modifying data. 3. Intention lock optimizes lock efficiency. 4. Record lock lock index record. 5. Gap lock locks index recording gap. 6. The next key lock is a combination of record lock and gap lock to ensure data consistency.

The main reasons for poor MySQL query performance include not using indexes, wrong execution plan selection by the query optimizer, unreasonable table design, excessive data volume and lock competition. 1. No index causes slow querying, and adding indexes can significantly improve performance. 2. Use the EXPLAIN command to analyze the query plan and find out the optimizer error. 3. Reconstructing the table structure and optimizing JOIN conditions can improve table design problems. 4. When the data volume is large, partitioning and table division strategies are adopted. 5. In a high concurrency environment, optimizing transactions and locking strategies can reduce lock competition.

In database optimization, indexing strategies should be selected according to query requirements: 1. When the query involves multiple columns and the order of conditions is fixed, use composite indexes; 2. When the query involves multiple columns but the order of conditions is not fixed, use multiple single-column indexes. Composite indexes are suitable for optimizing multi-column queries, while single-column indexes are suitable for single-column queries.

To optimize MySQL slow query, slowquerylog and performance_schema need to be used: 1. Enable slowquerylog and set thresholds to record slow query; 2. Use performance_schema to analyze query execution details, find out performance bottlenecks and optimize.

MySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.


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