WordPress DB Hook

    function dbhook_activate() {
        global $wpdb;

        // #region CREATING TABLE FOR Clusters
            $usn_cluster_tab = USN_CLUSTER_TAB;
            if($wpdb->get_var( "SHOW TABLES LIKE '$usn_cluster_tab'" ) != $usn_cluster_tab) {
                $sql = "CREATE TABLE `".$usn_cluster_tab."` (";
                    $sql .= "`ID` bigint(20) NOT NULL AUTO_INCREMENT, ";
                    $sql .= "`cluster_name` varchar(120) NOT NULL, ";
                    $sql .= "`cluster_info` varchar(255) NOT NULL, ";
                    $sql .= "`cluster_owner` bigint(20) NOT NULL, ";
                    $sql .= "`cluster_hostname` varchar(120) NOT NULL, ";
                    $sql .= "`cluster_secretkey` varchar(120) NOT NULL, ";
                    $sql .= "`cluster_capacity` int(12) NOT NULL DEFAULT '1000', ";
                    $sql .= "`date_created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, ";
                    $sql .= "PRIMARY KEY (`ID`), ";
                    $sql .= "UNIQUE  (`cluster_name`) ";
                    $sql .= ") ENGINE = InnoDB; ";
                $result = $wpdb->get_results($sql);
                
            }
        // #endregion

    } 
    add_action( 'activated_plugin', 'dbhook_activate' );