How to check Mysqli query empty or not? : I have trying this as like in MySQL but it is not working.Here is my code.Please help me.

    $sql_st_check="SELECT station_name FROM station WHERE station_code=".$station_code."";
    $sql_st_query=mysqli_query($connect,$sql_st_check);
    if ($sql_st_query && mysqli_num_rows($sql_st_query) > 0){
    }else{
    $sql_st_insert = "INSERT INTO station (id, station_code, station_name, station_title, url, datetime)
    VALUES ('', '".$station_code."', '".$station_name."', '".$station_title."', '".$station_url."', '".$time."')";
      $sql_st_query=mysqli_query($connect,$sql_st_insert);	
    }