警告：mysqli_connect()：MySQL 服务器已经消失

Question

I wrote a simple PHP code to connect to the MySQL server as below

<?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>";

but this generates the following errors. I found some topics regarding this issue in google and Stack Overflow. but those don't help me.

( ! ) 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

Answer 1

The error is here:

$hostname = "localhost:81";

You are not connecting to MySQL, but to Apache server. If you didn't change MySQL port just use

$hostname = "localhost";

Answer 2

you forget to specify the database name after entering database name try again. The syntax should be like this

<?php
$con = mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>

Answer 3

I found this useful for my case, stuck into same/similar problem.

<?php 
$host = "localdomain.local";
$port = 3306;

$mydatabase['default']['default'] = array(
  'database' => "db_name",
  'username' => "db_user",
  'password' => "",
  'host' => $host,
  'driver' => "mysql",
  'port' => $port,
  'prefix' => "",
);

if($mydatabase) {
    echo "true";
}

I hope this can be helpful for somebody...