Foreach insert query the best way

[vincekaribusana]

Hi i’ve got this code which works fine but I think it uses a lot of server resources because execute a query to the database for each user id stored in a group, is there any way to solve this problem?
Also I’ve tried to use prepared statement with no luck.

	$event_start_date = date('d-m-Y', strtotime($new_start_date));
        $notification = "Nuovo evento <span class='text-warning'><strong>$event_title</strong></span> inizia il $event_start_date";
        $notification_status = "0";
        $notification_category= "events";


        $sql = "SELECT user_join_id FROM user_group_join WHERE group_join_id='$event_group'";

		$result= mysqli_query($conn,$sql);

		$datas= array();

		if(mysqli_num_rows($result) > 0){

			while($row=mysqli_fetch_array($result, MYSQLI_ASSOC)){

			$datas[]= $row;

			}

		}

		foreach($datas as $data) {

		$id_cliente = $data['user_join_id'];

		$event_notification = mysqli_prepare($conn, "INSERT INTO user_notifications (notification_sent_by, notification_sent_to, notification_message, notification_time, notification_status, notification_category, notification_category_id) VALUES(?,?,?,now(),?,?,?)");
		mysqli_stmt_bind_param($event_notification, 'iisisi', $userid, $id_cliente, $notification, $notification_status, $notification_category, $event_id);
		mysqli_stmt_execute($event_notification);
		mysqli_stmt_close($event_notification);

		}

Many thanks for your help

[droopsnoot]

Could you not do something like:

$query = "INSERT INTO user_notifications (notification_sent_by, notification_sent_to, notification_message, notification_time, notification_status, notification_category, notification_category_id) 
SELECT '$userid', $user_join_id, '$notification', NOW(), '$notification_status',  '$notification_category', '$event_id' 
FROM user_group_join WHERE group_join_id='$event_group'";

I don’t know how to convert that into a prepared statement, perhaps in exactly the normal way. The idea is to combine the two queries and have the server do all the work.