在自定义WordPress数据库表中的文本字段中添加新行，而不会覆盖现有值

Question

I'm trying to add data to a text field, in a custom WordPress database table, on a new line without overwriting the value that is already in there.

I'm thinking it should go somewhat like this:

Get the value that is currently in the field, Add a line break to it, Concatenate to the new value, Update the table field with the new value.

The thing is, I have the new value being posted from a form.

My current code looks like this:

$tablename = 'st_support_tickets';

$data = array(
    'ticket_comment' => $_POST['ticket_comment']);

$where = array('ID' => $ticket_id);

$wpdb->update($tablename, $data, $where);
}

I'm not sure how I should go about getting the value that is already in the 'ticket_comment' field and add it to the value that is being POST by the form.

Any ideas?

Answer 1

Something like the below should work (not tested code, check for syntax issues)

$old_ticket_comment = $wpdb->get_var( "SELECT ticket_comment FROM $wpdb->st_support_tickets" );

$submitted_ticket_comment = $POST_['ticket_comment']; //you may want to sanitize

$new_ticket_comment = $old_ticket_comment.'<br />'.$submitted_ticket_comment;

$data = array('ticket_comment'=>$new_ticket_comment);
$where = array('ID' => $ticket_id);

$wpdb->update($tablename, $data, $where);