如何解决这个implode（）：传入的参数无效

Question

function getAddTrainingProvider($pretraining_provider_name,$courses,$url,$email,$phone,$login_user_id,$usertypeid,$status){ 

$responsess = json_decode($courses); 
$course_ids[] = implode(",",$responsess); 
$query= "INSERT INTO sz_pretraining_provider (pretraining_provider_name,pretraining_provider_course,pretraining_provider_url,pretraining_provider_email,pretraining_provider_phone,login_user_id,usertypeid,status) VALUES ('".$pretraining_provider_name."','".$course_ids."','".$url."','".$email."','".$phone."','".$login_user_id."','".$usertypeid."','".$status."')";
    $result         = mysqli_query($this->mysqli,$query);
    $id             = mysqli_insert_id($this->mysqli);
    return $id;
}

how to get array values from implode()