I have created 2 tables, Customer and Payment. A customer can have many payments, where payment have payment date and amount.
Now I want to display current month's unpaid customer, I really couldn't figured it out how to create the query.
Can anyone help?
I recommend going through the tutorials on the Lightswitch website for this. I believe there is a good example of something similar.
You can use the Customer data item to reference the Payments. Make sure there is a relationship over the tables. Then you can Edit Query from the left panel and choose Customer.Payment.'etc' as a parameter.
There are many more options from there, but this is a typical situation.