OOP-在哪里调用数据访问层?

我正在实现一个数据访问层(DAL),它基本上是一组具有(VB.NET)共享函数的类,用于实际执行数据库(CRUD)调用。我正试图找出在类层次结构中调用DAL的最佳位置。让我举个例子。

(pseudocode)

Namespace Dal

Public Class Customer

Public Shared Function Read(id As Integer) As Customer

Public Shared Function ReadList() As List(Of Customer)

Public Shared Sub Create(c As Customer)

'etc.

现在,我可以从表示层调用Dal,如下所示:

Me.DataGridView1.Datasource = Dal.Customer.ReadList

Public Function ReadList() As List(Of Customer)
    Return Dal.Customer.ReadList()
End Sub

Public Sub Create()
    Dal.Customer.Create(Me)
End Sub

这是“更干净”的OOP吗?或者,让演示文稿调用Dal,像我前面的例子一样传递业务对象,这是可以接受的做法吗:

Me.DataGridView1.Datasource = Dal.Customer.ReadList

Dim c As New Customer
c.Name = "Alpha Corporation"
c.Address1 = "123 Main Street"
Dal.Customer.Create(c)

感谢您的反馈。