mysql中的严格模式_MySQL
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mysql中的严格模式
很多集成的PHP环境(PHPnow WAMP Appserv等)自带的MySQL貌似都没有开启MySQL的严格模式，何为MySQL的严格模式，简单来说就是MySQL自身对数据进行严格的校验（格式、长度、类型等），比如一个整型字段我们写入一个字符串类型的数据，在非严格模式下MySQL不会报错，同样如果定义了char或varchar类型的字段，当写入或更新的数据超过了定义的长度也不会报错。
我认为这个对于编程来说没有任何好处，虽然我们尽量在代码中做数据校验。MySQL开启了严格模式从一定程序上来讲是对我们代码的一种测试，如果我们的开发环境没有开启严格模式在开发过程中也没有遇到错误，那么在上线或代码移植的时候将有可能出现不兼容的情况，因此在开发过程做最好开启MySQL的严格模式。
如何开启？
1.可以通过执行SQL语句来开启，但是只对当前连接有效，下面是SQL语句：
set sql_mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
2.通过修改MySQL的配置文件，在配置文件中查找sql-mode，将此行修改成为：
sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
如果查找不到sql-mode=则在[mysqld]下加入即可，推荐第二种方法，可以一劳永逸。
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