mysqli::query(): Couldn't fetch mysqli - php

Question

Warning: mysqli::query(): Couldn't fetch mysqli in C:\Program Files (x86)\EasyPHP-DevServer-13.1VC9\data\localweb\my portable files\class_EventCalendar.php on line 43
The following is my connection file:
<?php
if(!isset($_SESSION))
{
session_start();
}
// Create array to hold error messages (if any)
$ErrorMsgs = array();
// Create new mysql connection object
$DBConnect = #new mysqli("localhost","root#localhost",
NULL,"Ladle");
// Check to see if connection errno data member is not 0 (indicating an error)
if ($DBConnect->connect_errno) {
// Add error to errors array
$ErrorMsgs[]="The database server is not available.".
" Connect Error is ".$DBConnect->connect_errno." ".
$DBConnect->connect_error.".";
}
?>
This is my class:
<?php
class EventCalendar {
private $DBConnect = NULL;
function __construct() {
// Include the database connection data
include("inc_LadleDB.php");
$this->DBConnect = $DBConnect;
}
function __destruct() {
if (!$this->DBConnect->connect_error) {
$this->DBConnect->close();
}
}
function __wakeup() {
// Include the database connection data
include("inc_LadleDB.php");
$this->DBConnect = $DBConnect;
}
// Function to add events to Zodiac calendar
public function addEvent($Date, $Title, $Description) {
// Check to see if the required fields of Date and Title have been entered
if ((!empty($Date)) && (!empty($Title))) {
/* if all fields are complete then they are
inserted into the Zodiac event_calendar table */
$SQLString = "INSERT INTO tblSignUps".
" (EventDate, Title, Description) ".
" VALUES('$Date', '$Title', '".
$Description."')";
// Store query results in a variable
$QueryResult = $this->DBConnect->query($SQLString);
I'm not great with OOP PHP and I'm not sure why this error is being raised. I pulled this code from elsewhere and the only thing I changed was the #new mysqli parameters. Can anyone help me to understand what is going wrong?

Answer 1

Probably somewhere you have DBconnection->close(); and then some queries try to execute .
Hint: It's sometimes mistake to insert ...->close(); in __destruct() (because __destruct is event, after which there will be a need for execution of queries)

Answer 2

Reason of the error is wrong initialization of the mysqli object. True construction would be like this:
$DBConnect = new mysqli("localhost","root","","Ladle");

Answer 3

I had the same problem. I changed the localhost parameter in the mysqli object to '127.0.0.1' instead of writing 'localhost'. It worked; I’m not sure how or why.
$db_connection = new mysqli("127.0.0.1","root","","db_name");

Answer 4

Check if db name do not have "_" or "-"
that helps in my case