if you want to look into how to handle slowly changing dimension in QV, please look into the intervalmatch function and / or search the forum for intervalmatch or slowly changing dimension.
Looking at your sample it's hard to suggest a solution, because I personally don't understand your business case here.
In Sales History, you already have a link between EmployeeID and SalesOrderID (though, order id A2232 is missing in tab Sales). I don't understand how start date and end date correspond to Order date or hire start and end dates.
But maybe you just need to link the appropriate key field just by renaming them? Maybe renaming field SalesOrder to SalesOrderID using
LOAD
...
SalesOrder as SalesOrderID,
..
from ...;
This should already connect your three tabs.
Hope this helps (or you might be able to clarify what your requirements are).
Let me explain my cases clearly, there are four tables are there,
1. Sales Order Header.
2. Sales Order Details.
3. Sales History.
4. Employee Master.
Linking is Sales Order Header to Sales Order Details (SalesOrderID), Sales History to Sales Order Header (SalesHistoryID), Sales History to Employee Master (Employee ID).
Exp:
Sales data is available 2006 to 2009, but one of the emp hire date is 2007 Jan 1st but for him sales is showing 2006 onwards but it should not and Please find the attachment qvw and check for employee 289 hire date and sales for that.
