export sql results to excel

sql2excel.php

<?php
/*******EDIT LINES 3-8*******/
$DB_Server = "localhost"; //MySQL Server    
$DB_Username = "root"; //MySQL Username     
$DB_Password = "";             //MySQL Password     
$DB_DBName = "backoffice";         //MySQL Database Name  
$filename = "excelfilename";         //File Name
/*******YOU DO NOT NEED TO EDIT ANYTHING BELOW THIS LINE*******/    
//create MySQL connection   
$sql = 'Select * from $DB_TBLName';
$Connect = mysqli_connect($DB_Server, $DB_Username, $DB_Password, $DB_DBName) or die("Couldn't connect to MySQL:<br>" . $Connect->connect_error. "<br>" . $Connect->connect_errno);
//execute query 
$result = $Connect->query($sql) or die("Couldn't execute query:<br>" . $Connect->connect_error. "<br>" . $Connect->connect_errno);    
$file_ending = "xls";
//header info for browser
header("Content-Type: application/xls");    
header("Content-Disposition: attachment; filename=$filename.xls");  
header("Pragma: no-cache"); 
header("Expires: 0");
/*******Start of Formatting for Excel*******/   
//define separator (defines columns in excel & tabs in word)
$sep = "\t"; //tabbed character
//start of printing column names as names of MySQL fields
while ($fieldinfo = $result->fetch_field()) {
    echo $fieldinfo -> name . "\t";
}

print("\n");    
//end of printing column names  
//start while loop to get data
    while($row = mysqli_fetch_row($result))
    {
        $schema_insert = "";
        for($j=0; $j<mysqli_num_fields($result);$j++)
        {
            if(!isset($row[$j]))
                $schema_insert .= "NULL".$sep;
            elseif ($row[$j] != "")
                $schema_insert .= "$row[$j]".$sep;
            else
                $schema_insert .= "".$sep;
        }
        $schema_insert = str_replace($sep."$", "", $schema_insert);
        $schema_insert = preg_replace("/\r\n|\n\r|\n|\r/", " ", $schema_insert);
        $schema_insert .= "\t";
        print(trim($schema_insert));
        print "\n";
    }

Script was upgraded to php7