SQL creates a staging table for querying

Select    min (maxrank) as Minofmaxrankfrom    (select        max (rank) as Maxrank    from        tbl_core_staff    WHERE        St_ymd<=now () and        Ed_ymd>now () and        staff_cd in (', ', ', ', ', ', ', ', ', ', ', ', ', ', ', ', ",", ",", ",")    GROUP by        staff_cd    ) t1

Here is the rank of the largest value grouped from the Tbl_core_staff table query first and then the minimum value of the rank group for this maximum value

SQL creates a staging table for querying