mysqli::close()
(PHP 5, PHP 7)
关闭先前打开的数据库连接
说明
面向对象风格
mysqli::close(void): bool
过程化风格
mysqli_close(mysqli$link): bool
关闭先前打开的数据库连接
参数
- $link
仅以过程化样式:由mysqli_connect()或mysqli_init()返回的链接标识。
返回值
成功时返回TRUE
,或者在失败时返回FALSE
。
范例
See mysqli_connect().
参见
- mysqli::__construct() Open a new connection to the MySQL server
- mysqli_init() 初始化 MySQLi 并返回一个资源类型的值,这个值可以作为 mysqli_real_connect()函数的传入参数
- mysqli_real_connect() 建立一个 MySQL 服务器连接
Note with Francis' example, using the function name link() will throw an error at runtime as it is already a function within the language. see: http://php.net/manual/en/function.link.php
Since a lot of manual examples recommend to use a variable to initiate your connection, it is interesting to know that mysqli_close() will unset that variable, causing further connection attempts to fail. ex: $link = mysqli_connect($host, $user, $pw); if ($link) { // Database is reachable mysqli_close($link); } if ($link) { // Database unreachable because $link = NULL } Easiest solution for me is to initiate connection through a function. ex: function link() { global $host; global $user; global $pw; global $link; $link = mysqli_connect($host, $user, $pw); } link(); // Database is reachable mysqli_close($link) link(); // Database is reachable mysqli_close($link)
I've had situations where database connections appeared to persist following php execution. So, now, my __destructor function explicitly contains a $cxn->close(). It hurts nothing, and helps avoid memory leaks.