Query Tables (Looking up data from another table to make 1 table)

Query Tables (Looking up data from another table to make 1 table)

I have 2 tables created by importing data on a nightly basis.  One table lists sales.  The other table lists refunds (which could happen up to 30 days after the sale).  I want to create a table which lists all of this data in one shot.  In essence you would have a date column, a thread column (this is the common value that ties sales and refunds together), and an amount column.  All refunds would be negative and all sales would be positive numbers in the amount column.  It would be like appending one database at the bottom of the other to make 1 giant database.  In this way, I could then build reports with Dynamic date ranges, aggregate formulas which clearly show refunds vs. sales, and everything that goes along with it.  Any help with this would be GREATLY appreciated.