将mysql更改为mysqli [复制]

I am trying to convert from mysql to mysqli. But whenever i change the mysql_num_rows and mysql_query to mysqli_num_rows and mysqli_query.

The problem shows

mysqli_query() expects at least 2 parameters

my Code:

         $sqlCount = "select * from eventcalendar where eventDate='".$dateToCompare."'";
         $noOfEvent = mysql_num_rows(mysql_query($sqlCount));
            if($noOfEvent >= 1){
                //echo "";
             }
            }

</div>

 $sqlCount = "select * from eventcalendar where eventDate='".$dateToCompare."'";
 $result = mysqli_query($conn, $sqlCount);

    // Return the number of rows in result set
    $rowcount=mysqli_num_rows($result);

    if($rowcount>=1){
            //echo "";
    }