I am trying to create a simple line graph with two sets of data. For example, I have a customer table, that has the Membership Date. So I want one line graph to show the number of Customers growing. I have a second table called Purchases which has a column Purchase Date. So on the same graph, I want another line showing the number of Purchases growing.
The problem I have is that the line graph is only using one set of dates for the Y-axis. I don't know how to associate # of Purchaes to Purchase Date and # of Customers to Membership Date.