###Hello, I have 2 main questions:

###Question 1: Discrepancies between the ERD and the text description. While doing the SQLite table code, I found out that some details are inconsistent between the ERD and the text description:

• There is no mention of an email field and its data description for customers, even though it is present in ERD
• In the text description, it can be assumed that the contact phone number would belong to table Client, however in the ERD it belongs under Customer
• It is unclear whether details about who is paying for who would belong under Customer or Patient (although I assume this would be up to how we implement it)

###Question 2: Adding additional fields for entity identification and linking

Can we add additional fields for linking entities across tables (.ie between an appointment and its invoice)?