This seems to be a representation of what you are looking for.

create table #Client

(

ClientID int identity,

Name char(2)

)

insert #Client

select 'C1' union all

select 'C2' union all

select 'C3'

create table #Orders

(

OrderID int identity,

ClientID int,

OrderName char(2)

)

insert #Orders

select 1, 'O1' union all

select 1, 'O2' union all

select 2, 'O3' union all

select 2, 'O4' union all

select 3, 'O5' union all

select 3, 'O6'

create table #OrderInfo

(

OrderInfoID int identity,

OrderID int,

Priority int

)

insert #OrderInfo

select 1, 7 union all

select 1, 1 union all

select 2, 9 union all

select 2, 3 union all

select 3, 4 union all

select 5, 2 union all

select 7, 5 union all

select 7, 8 union all

select 8, 0

select c.Name

from #OrderInfo oi

join #Orders o on oi.OrderID = o.OrderID

join #Client c on c.ClientID = o.ClientID

group by c.Name

order by max(oi.Priority)

drop table #Client

drop table #Orders

drop table #OrderInfo

Notice how I posted this in a consumable format?

I would HIGHLY recommend you change your naming conventions. You should not use a datatype prefix on your columns. I am assuming that things like "autClientId" and "vchName" mean "AutoNumberClientID" and "VarcharName". Not only does that make it difficult to find your columns, it will cause you untold pain when you have to change a datatype. You will end up with either LOTS of code to rework or prefixes that don't match anymore. Just don't it at all. It may seem like a good idea at first but you will soon realize how horrible that really is.