System has many users belongs to a company. Admin user of the company can entry customers and each customer may have invoices with payment amount. The customer invoice amount need to be paid and should be inserted in double entry system in transaction master table.
Data Models are followings:
My initial approach will be:
Company will have a one to many relationship with users
in invoice table, the details will be saved.
My questions are:
Yes, you need to create a relationship between customers and invoices table. Every invoice will have one customer. Every customer will have none, one, or many invoices. You will need a unique identifier to be stored in each file.
Transaction file is a much deeper subject. I assume you mean Ledger Transactions. Generally you will group a transaction with one or more debit entries matched with one or more credit entries with an associated reference number which will point to the invoice transaction. You would group references in a batch, usually called a session, and assign a session number at batch posting time which would have the post date.
These are the basic minimum answers to a very vague question on a potentially complex subject, but hopefully it will help get you started in the right direction for further research.