Question

I have a dimensions table

@dimensions
Dateid  Rep Mkt Prodgroup
201111  002 S   001
201111  002 R   001
201111  002 S   002
201111  002 R   002
201111  002 S   003
201111  002 R   003
201111  002 S   004
201111  002 R   004
...

I want to join it with this table to include the percentage.

@percentageincrease
Prodgroup   Mkt Percent
ALL         S   1.05
ALL         R   1.06
002         S   1.07
002         R   1.08
003         S   1.09
003         R   1.10

I want to join them on Mkt and Prodgroup where @dimensions.Prodgroup IN @percentageincrease.Prodgroup and if not in then to join on the ALL. So the output table would be

Dateid  Rep Mkt Prodgroup   Percent
201111  002 S   001         1.05 // joined on ALL
201111  002 R   001         1.06 // joined on ALL
201111  002 S   002         1.07 // joined on 002
201111  002 R   002         1.08 // joined on 002
201111  002 S   003         1.09 // joined on 003
201111  002 R   003         1.10 // joined on 003
201111  002 S   004         1.05 // joined on ALL
201111  002 R   004         1.06 // joined on ALL
...

As my join condition I have tried

on case p.Prodgroup 
    when N'ALL' 
    then d.prodgrpid 
    else p.Prodgrpid = d.prodgrpid
AND p.Mkt = d.Mkt

but it gave me

Dateid  Rep Mkt Prodgroup   Percent
201111  002 S   001         1.05
201111  002 R   001         1.06
201111  002 S   002         1.07
201111  002 R   002         1.08
201111  002 S   002         1.05 //Joined on ALL
201111  002 R   002         1.06 //Joined on ALL
201111  002 S   003         1.09
201111  002 R   003         1.10
201111  002 S   003         1.05 //Joined on ALL
201111  002 R   003         1.06 //Joined on ALL
201111  002 S   004         1.05
201111  002 R   004         1.06
...

where the tuples which were in the @percentageincrease table were also joined on the ALL condition.

This is being run on SQL Server 2008 as a stored procedure as part of a larger query.

Answer 1

Assuming the table structures

declare @dimensions table 
    (Dateid varchar(10),  Rep varchar(10), Mkt varchar(10),Prodgroup varchar(10))
declare @percentageincrease table 
    (Prodgroup varchar(10),  Mkt varchar(10), [Percent] decimal(9,5))

then

select 
     d.*, 
     isnull(pinc.[Percent], pincall.[Percent]) 
from @dimensions d
    left join @percentageincrease pinc 
        on d.Mkt = pinc.Mkt
      and d.Prodgroup = pinc.Prodgroup
    left join @percentageincrease pincall
        on d.Mkt = pincall.Mkt
      and pincall.Prodgroup ='all'