Basically what is happening is that one row in one of the tables is being joined to two rows in another table. The two rows that are being joined are probably unique, but you aren't including the column/s that make them unique in the query (I don't know for sure which tables are causing it because you didn't give input data).
You need to either add those column/s to the query (if you do in fact need them) or add the DISTINCT keyword to exclude the duplicates.
For example:
create table #Customers
(
CustomerID int,
CustomerName varchar(20)
)
create table #Orders
(
OrderID int,
CustomerID int,
OrderDate datetime
)
insert #Customers
select 1, 'Mickey Mouse' union all
select 2, 'Donald Duck' union all
select 3, 'Goofy'
insert #Orders
select 1, 1, '1/1/2007' union all
select 2, 1, '1/1/2007' union all
select 3, 2, '1/2/2007' union all
select 4, 2, '1/2/2007' union all
select 5, 3, '1/3/2007' union all
select 6, 3, '1/4/2007'
--Query with duplicates
select C.CustomerName, O.OrderDate
from #Customers C
inner join #Orders O on C.CustomerID = O.CustomerID
--Query 1 without duplicates
select C.CustomerName, O.OrderID, O.OrderDate
from #Customers C
inner join #Orders O on C.CustomerID = O.CustomerID
--Query 2 without duplicates
select distinct C.CustomerName, O.OrderDate
from #Customers C
inner join #Orders O on C.CustomerID = O.CustomerID
drop table #Customers
drop table #Orders
Duplicate results
Posted - 03/22/2007 : 16:10:30
Cows?