How to fix mysql database connection error?

Question

PHP

Hello!
I'm trying to run PHP on openserver.
Created a database using phpmyadmin.
Once I tried, I can not get a connection to the MySQL database in any way

<?php
$first_name         = $_POST['firstname'];
$last_name          = $_POST['lastname'];
$when_it_happened  = $_POST['whenithappened'];
$how_long          = $_POST['howlong'];
$how_many          = $_POST['howmany'];
$alien_description = $_POST['aliendescription'];
$what_they_did     = $_POST['whattheydid'];
$fang_spotted      = $_POST['fangspotted'];
$email             = $_POST['email'];
$other             = $_POST['other'];

$dbc = mysqli_connect('127.0.0.1:3306', 'mysql', 'mysql', 'aliendatabase')
    or die ('Ошибка соединения с MySQL - сервером.');

$query = "INSERT INTO aliens_abduction (first_name, last_name, when_it_happened, how_long, " .
    "how_many, alien_description, what_they_did, fang_spotted, other, email) " .
    "VALUES ('$first_name', '$last_name', '$when_it_happened', '$how_long', '$how_many', " .
    "'$alien_description', '$what_they_did', '$fang_spotted', '$other', '$email')";

$result = mysqli_query($dbc, $query) or die ('Ошибка при выполнении запроса к базе данных.');

mysqli_close($dbc);
?>

Always returns "Error while executing database query". How to understand what could be the reason?

Answer 1

if(!isset($_SESSION[ 'admincp' ]) && !isset($_SESSION['login'])))

Answer 2

Anything. See the error in mysqli_error() .
It can be assumed that one of the inserted data contains a single quote. Since you are not using placeholders, or at least escaping, any special character in the data can cause an error.