SQL Query Problem

Question

Hello.

 

 I Have Two Table From Which I want to Create Query

 

1) Table - Purchase 

PurchaseID,ItemID,PurchaseDate,PurchaseQuantity 

 

2) Table- Sale 

SaleID,ItemID,SaleDate,SaleQuantity  

 

 

Now I want to  Create A query to Give this Result Between Two Dates From Both Tables

 

ItemID

TotalPurchaseQuantity

TotalSaleQuantity

 

 

 

The Problem is Date From Which Table I should Give Date To Query (Sale Table Or Purchase)