While working on data model building, we often encounter a situation where we want to have some fields added from one table into another to do some sort of calculations. In such situations, we use the option of joining those tables based on the common fields between them.

Let's understand how we can use joins between tables with a simple example.

Assume you want to calculate the selling price of a product. The information you have is SalesQty in Sales Table and UnitPrice of product in Product Table. The calculation for getting the sales price is UnitPrice * SalesQty. Now, let's see what output we get when we apply a join on these tables: