[Discussion] MVC --> model-> Data Manage-> Database: SQL Server vs access

Requirements:
1. The starting point of the discussion is not the technical research, but the reasons for choice.
2 Based on ASP. NET

Questions:
In a pattern like MVC or enterprise architecture, taking petshop provided by MS as an example, SQL databases are used, but for developers (like me ), the customer may require more access databases. Is it necessary to use SQL databases in such projects?

Your own ignorance:
MVC = model + view + control. I am not going to discuss this design pattern here. I just want to hear about the selection of databases used in data management in the model and the reasons for the selection. My customers seldom require SQL databases, so I have been thinking about whether to adopt the MVC pattern after I have done some projects. Because I think the MVC mode is used to accomplish the task, the efficiency and maintenance are not the same as the previous mode (that is, the required functions are completed on various pages ).Code.
Welcome to the discussion!