我该如何解决这个问题：致命错误：在非对象上调用成员函数query（）

Question

我在向数据库添加结果时遇到问题。这是我的链接代码。

$startingunix = strtotime($dates . " " . $startingtime); //
$endingunix = strtotime($dates . " " . $endingtime);

$servername = "localhost";
$username = "x";
$password = "x";
$dbname = "josfei6_ge";


// Create connection
$connection = mysqli_connect($servername, $username, $password,      $dbname);

// Check connection
if (!$connection) {
die("Connection failed: " . mysqli_connect_error());
}

date_default_timezone_set("America/Los_Angeles");

global $mysqli;

$sql="SELECT * FROM `events` WHERE `description` = '$desc' ORDER BY    starttime;";

$records=mysqli_query($connection, $sql);

$numberofevents = 0;

$okay = 0;




while($eventnow=mysqli_fetch_assoc($records)){}

当我尝试向数据库添加数据时出现错误：

$dbconnection->query($sql);

它给我一个错误：     fatal error: Call to a member function query() on a non-object

有人有建议吗？