PHP database operations
Which databases does PHP support?
Database extensions
A database in PHP may have one or more extensions, including official ones and those provided by third parties. Commonly used extensions for Mysql include the native mysql library, you can also use the enhanced version of mysqli extension, and you can also use PDO for connection and operation.
Different extensions provide basically similar operation methods. The difference is that they may have some new features and the operation performance may be different.
mysql extension method for database connection:
更新与删除数据
数据的更新与删除相对比较简单,只需要构建好相应的sql语句,然后调用mysql_query执行就能完成相应的更新与删除操作。 同样的删除可以使用类似以下的代码: 对于删除与更新操作,可以通过mysql_affected_rows函数来获取更新过的数据行数,如果数据没有变化,则结果为0。
关闭MySQL连接
当数据库操作完成以后,可以使用mysql_close关闭数据库连接,默认的,当PHP执行完毕以后,会自动的关闭数据库连接。 虽然PHP会自动关闭数据库连接,一般情况下已经满足需求,但是在对性能要求比较高的情况下,可以在进行完数据库操作之后尽快关闭数据库连接,以节省资源,提高性能。 在存在多个数据库连接的情况下,可以设定连接资源参数来关闭指定的数据库连接。
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以上就介绍了PHP数据库操作,包括了方面的内容,希望对PHP教程有兴趣的朋友有所帮助。

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