select class by excul id

select
       mc.class_id,
        mc.class_name,
       msl.abbreviation,
       myl.description,
       tslr.order_number
from ms_excul_mapping
    join ms_excul me
        on ms_excul_mapping.excul_id = me.excul_id
               and me.deleted_at is null
    join ms_excul_mixed_year_level memyl
        on ms_excul_mapping.excul_mixed_id = memyl.excul_mixed_id
               and memyl.deleted_at is null
    join tr_school_level_relation tslr
        on tslr.school_location_id = memyl.school_location_id
               and tslr.school_level_id = memyl.school_level_id
               and tslr.year_level_id = memyl.year_level_id
               and tslr.deleted_at is null
    join tr_academic_calendar tac
        on tac.school_level_relation_id = tslr.school_level_relation_id
               and tac.deleted_at is null
               and tac.academic_year = me.academic_year
    join ms_class mc
        on mc.academic_calendar_id = tac.academic_calendar_id
                and mc.deleted_at is null
    join ms_school_level msl
        on msl.school_level_id = tslr.school_level_id
                and msl.deleted_at is null
    join ms_year_level myl
        on myl.year_level_id = tslr.school_level_relation_id
                and myl.deleted_at is null
where ms_excul_mapping.excul_id = 3859
  and ms_excul_mapping.deleted_at is null
  and tac.period_id = (select max(period_id) from ms_period)
group by
         msl.abbreviation,
         myl.description,
         tslr.order_number,
         mc.class_id