Results based on a date range

Hi, I now have my date range working, but how would I specify in either the recordset or the php code (or both) that I need results based upon just that date range? For instance, if an admin does a search of an item in the inventory db and wants specific information for how many of that item was sold in that specific date range, where would I implement this? And how?

Would I join tables and then write this in my query within my recordset?
How would I then get this information to display?
Would I need to use DataAssist to bind the results to my text fields?
Would I need to make a hidden search on my results page to produce the results I am looking for?

Thanks!