Does model or controller perform CRUD in asp.net? - asp.net

Question

I'm quite new to ASP.NET and MVC and I get confused about the CRUD logic. I found the following explanation from a resource, however, as far as I know, the CRUD are performed in controller, for instance, they are achieved by the actions such as Index, Create, DeleteConfirm, Edit, etc. Am I misunderstanding this concept?

Answer 1

According to the picture above, the model is the "Doamin Model", it is not "M" from MVC as Slava Utesinov said, it's a concept of DDD(Domain-Driven Design).
In ASP.NET MVC, the traditional way that where we do CRUDs are in actions of controllers, and your understand is right.
In DDD concept(Domain-Driven Design), we do CRUDs in domain model.
Whatever we use DDD architecture or traditional ways, we need to do that based on the basic MVC architecture.
More information about DDD for your reference:
Domain-Driven Design – What is it and how do you use it?

Answer 2

Yes you are right, CRUD operations can perform in Controller by actions and Model can help to achieve that. Model is nothing but a class which will having properties in that.
For example: "Employee" is class which is having different properties like "FirstName, LastName, EmployeeID, Email, DateOfJoining etc.". Now if you have to perform CRUD operation on this then you have to write code in Controller Class under different actions by using this "Employee" model class.
Model only cannot perform CRUD operation.

Answer 3

You can do it wherever you want it but you will be breaking the concept which is "Separation of Concerns". The Controller should only be concern of which view or which action it is going to call or perform. The Model should only be used how your data is going to be structured, it is usually similar to how your database properties look. In short, your Model (class model) should have minimal thinking. For example, you have a table called Person with columns as IDPerson, FirstName,LastName. Your model should be something similar to this:
public class Person {
public IdPerson {get;set;}
public FirstName {get;set;}
public LastName {get;set;}
}
Let's say you have a view that shows the detail of a person which could be something
like this:
public class PersonController : Controller
public ActionResult GetPerson(int IdPerson){
PersonBusinessLogic pbl = new PersonBusinessLogic();
Person p = pbl.GetPersonFromDatabase(id); //To add more consistency, the data access is on a separate class for better maintenance and to emphasize "Separation of Concerns"
ViewResult vr = new ViewResult()
{
ViewName = this.View,//This is where you assign the page if you have other pages for this action
ViewData = new ViewDataDictionary(ViewData)
{
Model = p
}
};
return vr;
}
For your crude:
[HttpPost]
public ActionResult CreatePerson(Person p)
{
try
{
if (ModelState.IsValid)
{
PersonBusinessLogic pbl = new PersonBusinessLogic();
pbl.CreatePersonToDatabase(p);
return RedirectToAction("Index", "Home");
}
}
catch(Exception ex){
ModelState.AddModelError("",ex.Message);
}
return View(p);
}
[HttpPost]
public ActionResult UpdatePerson(Person p)
{
try
{
if (ModelState.IsValid)
{
PersonBusinessLogic pbl = new PersonBusinessLogic();
pbl.UpdatePersonToDatabase(p);
return RedirectToAction("Index", "Home");
}
}
catch(Exception ex){
ModelState.AddModelError("",ex.Message);
}
return View(p);
}
[HttpPost]
public ActionResult DeletePerson(Person p)
{
try
{
if (ModelState.IsValid)
{
PersonBusinessLogic pbl = new PersonBusinessLogic();
pbl.DeletePersonByIDFromDatabase(p.IdPerson);
return RedirectToAction("Index", "Home");
}
}
catch(Exception ex){
ModelState.AddModelError("",ex.Message);
}
return View(p);
}
To give you a better idea, Find some article on how MVC is greatly applied as a concept then you will greatly appreciate the learning process.