Optimal design business layar: separate model from logic?

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patterns

I'm new to designing a business logic layar and I'm searching for the optimal design.

What is a better way for the design of the business logic layar:
1. Put the business logic within the business entities.
2. Have a static model and perform de business logic by making use of adapters.

See the examples below.

What is better to do and what are de pro's and cons? Any advise would be greatly appreciated!

Design 1

Dim Customer as New Customer(1)

Customer.Load()
Customer.Name = "John"
Customer.Update()

Design 2

Dim CustomerAdapter As New CustomerAdapter
Dim Customer As New Customer

Customer = CustomerAdapter.GetCustomerByID(1)
Customer.Name = "John"
Customer.Update