WordPress插件创建触发器无法正常工作

Question

So I have a create trigger script which works absolutely great in PHP MyAdmin in MySQL.

But when i try to fire the exact same trigger SQL script within my plugin. It fails to be created in MySQL and the most annoying part is that WordPress doesn't give me any errors at all.

I'm trying to create my trigger through a WordPress activate function in PHP within my plugin.

All my other SQL scripts works in this activate function. It's just the trigger which isn't working.

I'm quite sure the problem lies within how i fire the script in the end

Example:

        global $wpdb;
        $comments = $wpdb->prefix . "comments";

        $createTrigger = 
                        "
                        DROP TRIGGER IF EXISTS upd_trigger;
                        DELIMITER //
                        CREATE TRIGGER upd_trigger
                        AFTER INSERT 
                            ON  $comments 
                            FOR EACH ROW 

                        BEGIN

                        //some code

                        END //
                        DELIMITER ;"; 

        require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
        $wpdb->query( $createTrigger ); 

I have also tried the following functions:

dbDelta( $createTrigger );

mysqli_multi_query( $wpdb->dbh, $createTrigger );

So i'm kind of lost on why this isn't working.

Any help much appreciated.