PHP.ini causes Warning: mysqli_error() expects parameter 1 to be mysqli, null given in/sys/index.php on line 19 [duplicate]

Answer 1

function.php

function consql()
{
    $con=mysqli_connect("host","BDusername","DBPassWord","DB") or die( mysqli_error($con));
    return $con;
}

index.php

require_once"inc/function.php";
$con = consql();

explanation : why no error appears in your localhost‌? is it a PHP.ini problem ?

maybe errors are hidden on your localhost or mysqli_query runs with no problem there. but there is a problem on your host, such as connection problem, missing or broken database table or etc... base on your code, when no error occurs, mysqli_error() wont run and you dont get error

Answer 2

You can use

function consql(&$con){
  $con=mysqli_connect("host","BDusername","DBPassWord","DB") or die( mysqli_error($con));
}

So this is call by reference and $con can use at any page once you call the function

Or use global $con; before the connection line