php - 新的 mysqli 与 mysqli_connect

Question

newmysqli和 和有什么不一样mysqli_connect？我知道执行查询是不同的；
比如：mysqli->query()和mysqli_query()
为什么会有两种不同的类型，有什么区别？

Answer 1

一种用于过程式编程，另一种用于 OOP 式编程。两者都有相同的目的；Open a new connection to the MySQL server

OOP 样式用法

$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'my_db');

程序样式的使用

$link = mysqli_connect('localhost', 'my_user', 'my_password', 'my_db');

参考：PHP手册

Answer 2

就在@Hanky Panky 上。我还要添加 PHP 文档：

http://www.php.net/manual/en/mysqli.construct.php

笔记：

仅面向 OO 语法：如果连接失败，仍会返回一个对象。要检查连接是否失败，请使用 mysqli_connect_error() 函数或 mysqli->connect_error 属性，如前面的示例中所示。

So error handling is just one difference.

Answer 3

I just found a subtle but interesting difference between the two.

If you encounter a connection error with mysqli_connect (like $connection = mysqli_connect()), no mysql info will be returned to the $connection variable. As such, you will not be able to identify the error with myqli_errno($connection).

However if you encounter a connection error using new mysqli (like $connection = new mysqli()), the mysql info WILL be returned and you can check the error with $connection->connect_errno.

Knowing this, I'd opt for new mysqli.

Oops... Just saw answer from Rick Buczynski and realized after posting that I'm restating what he said, but his reply is more informative.