Case Overriding where? - sql

Question

Ok so i have one table with lets call it A(there are more items here):
ITEMID NAME
10001 Boat
I have another table lets call it B(there are more items here):
Itemid Price Pricetype Dimension Valid_from Valid_To
10001 10 1 Allblank 2014-10-10 2014-10-25
10001 5 2 200 2014-10-09 2014-10-20
10001 99 2 200 2014-10-08 2014-10-10
10001 20 1 Allblank 2014-10-08 2014-10-10
10001 22 2 500 2014-10-10 2014-10-19
Price type determines wherever item is on sale or no so i want to list the regular price at its dimension and the sales price at the dimension so the table should look like this (assuming that 1 is regular price and 2 is sale price):
Itemid Itemname RegularPrice DiscountPrice200 DiscountPrice500
10001 boat 10 5 22
I've inner joined tables, but i cant manage to manage the fields right , case statement returns a lot of duplicates on inner join. I hope i made myself clear :)
My query:
SELECT a.itemid,
case when b.inventdimid = '00000101_090' and (b.labelissue ='1' or b.labelissue = '2' and (b.todate > getdate() or b.todate ='1900-01-01 00:00:00.000') ) then b.amount else null end as Price500
FROM a
inner join b
on a.itemid = b.itemrelation

Answer 1

Try this query:
SELECT b.itemid,
a.name,
b.price,
b200.price,
b500.price
FROM tb b
JOIN ta a
ON b.itemid = a.itemid
JOIN tb b200
ON b.itemid = b200.itemid
AND b200.valid_to > getdate()
AND b200.pricetype = 2
AND b200.dimension = 200
JOIN tb b500
ON b.itemid = b500.itemid
AND b500.valid_to > getdate()
AND b500.pricetype = 2
AND b500.dimension = 500
WHERE b.valid_to > getdate()
AND b.pricetype = 1