警告：mysqli_connect()：MySQL 服务器已消失

我编写了一个简单的 PHP 代码来连接到 MySQL 服务器，如下所示

<?php

$username = "root";
$password = "Kepwd";
$hostname = "localhost:81";

//connection to the database
$dbhandle = mysqli_connect($hostname, $username, $password)
  or die("Unable to connect to MySQL");
echo "Connected to MySQL<br>";

但这会产生以下错误。我在 google 和 Stack Overflow 中找到了一些有关此问题的主题。但那些对我没有帮助。

( ! ) Warning: mysqli_connect(): MySQL server has gone away in C:\wamp\www\SSDConsultingNew\inc\test.php on line 8
Call Stack
#   Time    Memory  Function    Location
1   0.0014  240936  {main}( )   ..\test.php:0
2   0.0014  241528  mysqli_connect ( )  ..\test.php:8

( ! ) Warning: mysqli_connect(): Error while reading greeting packet. PID=10612 in C:\wamp\www\SSDConsultingNew\inc\test.php on line 8
Call Stack
#   Time    Memory  Function    Location
1   0.0014  240936  {main}( )   ..\test.php:0
2   0.0014  241528  mysqli_connect ( )  ..\test.php:8

( ! ) Warning: mysqli_connect(): (HY000/2006): MySQL server has gone away in C:\wamp\www\SSDConsultingNew\inc\test.php on line 8
Call Stack
#   Time    Memory  Function    Location
1   0.0014  240936  {main}( )   ..\test.php:0
2   0.0014  241528  mysqli_connect ( )  ..\test.php:8
Unable to connect to MySQL

错误在这里：

$hostname = "localhost:81";

您没有连接到 MySQL，而是连接到 Apache 服务器。如果你没有更改 MySQL 端口，只需使用

$hostname = "localhost";