CREATE TRIGGER bu_projects_tomerge_4
BEFORE UPDATE OF
    resolve
ON
    projects_tomerge
FOR EACH ROW WHEN
    NEW.resolve = 1 AND
    OLD.parent_id != 0
BEGIN

    SELECT debug(
        'TRIGGER bu_projects_tomerge_4',
        OLD.project_id
    );

    UPDATE
        projects
    SET
        parent_id = (
            SELECT
                project_updates.parent_id
            FROM
                project_updates
            INNER JOIN
                updates
            ON
                updates.id = project_updates.update_id
            WHERE
                project_updates.project_id = OLD.project_id AND
                project_updates.parent_id IS NOT NULL
            ORDER BY
                updates.mtime DESC,
                updates.uuid
            LIMIT
                1
        )
    WHERE
        id = OLD.project_id
    ;

END;