Question

I tried to create one more new ASP.NET MVC application (with Entity Framework) and a little frustrated again.

For example, I have a database with the following tables:

Table Users:

CREATE TABLE [dbo].[Users](
 [ID] [int] IDENTITY(1,1) NOT NULL,
 [FirstName] [nvarchar](50) NOT NULL,
 [LastName] [nvarchar](50) NOT NULL,
 [Title] [nvarchar](max) NOT NULL,
 [Company] [nvarchar](50) NOT NULL,
 [Phone] [nvarchar](50) NULL,

[CompanyUrl] [nvarchar](max) NULL,
 [EmailPlainText] [bit] NULL,
 [ProfileImage] [nvarchar](max) NULL,
 [ProfileDescription] [nvarchar](max) NULL,
 [ProfileDocument] [nvarchar](max) NULL,
 [ProfileWebSite] [nvarchar](max) NULL,
 [Facebook] [nvarchar](max) NULL,
 [Linkedin] [nvarchar](max) NULL,
 [MySpace] [nvarchar](max) NULL,
 [Twitter] [nvarchar](max) NULL,
 CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED 



CREATE TABLE [dbo].[Services](
 [ServiceID] [int] IDENTITY(1,1) NOT NULL,
 [ServiceName] [nvarchar](250) NOT NULL,
 [ServiceOrder] [int] NOT NULL,
 CONSTRAINT [PK_Services] PRIMARY KEY CLUSTERED



CREATE TABLE [dbo].[UserServices](
 [UserID] [int] NOT NULL,
 [ServiceID] [int] NOT NULL,
 CONSTRAINT [PK_UserServices] PRIMARY KEY CLUSTERED



CREATE TABLE [dbo].[GeographicalAreas](
 [GeoAreaID] [int] IDENTITY(1,1) NOT NULL,
 [GeoAreaName] [nvarchar](250) NOT NULL,
 CONSTRAINT [PK_GeographicalAreas] PRIMARY KEY CLUSTERED



CREATE TABLE [dbo].[UserGeoAreas](
 [UserID] [int] NOT NULL,
 [GeoAreaID] [int] NOT NULL,
 CONSTRAINT [PK_UserGeoAreas] PRIMARY KEY CLUSTERED

so, how can we see, there is : one table for User info, 2 table-dictionaries (Services and GeographicalAreas) and 2 tables (UserServices and UserGeoAreas) for relationship many-to-many between User and table-dictionaries. Standard situation

Also we have 3 different pages :

1. On the first page should be displayed :

FirstName, LastName, Title, Company, Services (linked to an user) and GeoAreas (linked to an user)

1. On the second page:

FirstName, LastName, Title, Company, Facebook, Linkedin and Twitter

1. On the third page only FirstName, LastName, ProfileImage and ProfileDocument

Also, on the filrst page should be validate attributes like “required” etc

so, how to realize it?

The first way:

Creating 3 different view-classes (3 different models) for each page, creating 3 different linq-requests (3 public methods in a class-repository), each method of controller (for each page) calls the appropriate method in class-repository

The second way:

Create one common view class (which includes all requires fields for 3 pages), one common method in a class-repository, which fills all fields, each method of controller calls the method of repository

The third way:

Creating 3 different view-classes (3 different models) for each page, one common class (which includes all requires fields for 3 pages), one method in a class-repository, which fills all fields, 3 converters to move data from the common class to the appropriate view-class.

Answer 1

When in doubt, go with the Single Responsibility Principle:

In object-oriented programming, the single responsibility principle states that every object should have a single responsibility, and that responsibility should be entirely encapsulated by the class. All its services should be narrowly aligned with that responsibility.

Your option 1 would be the correct one. Every view should have its own distinct controller and its own distinct view model (ideally being retrieved by its own distinct call to a repository).