CRUD in MVC repository - asp.net-mvc

Question

I have created a repository data layer in my MVC web application, and want to use it for my CRUD methods. But I came to think of situations where I want to do something like:
If record does not exist
create record
else
update record
But how does this fit into CRUD? Is this two-in-one operation logic supposed to be kept in the controller?

Answer 1

I think the repository should take care of that, the controller should be as light as possible:
At repository level:
public bool CreateUpdate(Type model)
{
var record = db.FirstOrDefault(x=> x.Id == model.Id);
if(record == null)
{
Create(model);
}
else
{
Update(model);
}
}
public bool Create(Type model)
{
//create logic here
}
public bool Update(Type model)
{
//update logic here
}

Answer 2

This can be done with this code
var data = db.tableName.where(x=> x.Id == model.Id).FirstOrDefault();
if(data== null)
{
db.FAQCategories.Add(model);
db.SaveChanges();
}
else
{
db.Entry(model).State = EntityState.Modified;
db.SaveChanges();
}

Answer 3

public IActionResult Create()
{
return View();
}
// POST: AdminPanel/Students/Create
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(Student student)
{
if (!ModelState.IsValid)
{
return View();
}
student.Image = await student.Photo.SaveFileAsync(_environment.WebRootPath, "images");
await _context.Students.AddAsync(student);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
// GET: AdminPanel/Students/Edit/5
public async Task<IActionResult> Update(int? id)
{
if (id == null)
{
return BadRequest();
}
var student = await _context.Students.FindAsync(id);
if (student == null)
{
return NotFound();
}
return View(student);
}
// POST: AdminPanel/Students/Edit/5
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Update(int? id, Student newstudent)
{
if (id==null)
{
return BadRequest();
}
var oldstudent = _context.Students.Find(id);
if (oldstudent == null)
{
return NotFound();
}
if (!ModelState.IsValid)
{
return View();
}
var path = Helper.GetPath(_environment.WebRootPath, "images", oldstudent.Image);
if (System.IO.File.Exists(path))
{
System.IO.File.Delete(path);
}
newstudent.Image = await newstudent.Photo.SaveFileAsync(_env.WebRootPath, "images");
oldstudent.Image = newstudent.Image;
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
public async Task<IActionResult> Delete(int id)
{
if (id == null)
{
return BadRequest();
}
var student= _context.Students.Find(id);
if (student== null)
{
return NotFound();
}
_context.Students.Remove(student);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
}
}