SqlApi not updating database

Question

I have made a C# Sql API. So far the Read, create and delete work, that means the connection is good, but somehow it is not saving the information in the database. In the code I made some writelines so you can see some output. I would really appreciate if you would take a look.

CMD (output):

Postman request:

KlantController:

namespace Controllers
{
    [ApiController]
    [Route("api/Klant")]
    [Produces("application/json")]
    public class KlantController : ControllerBase
    {

        private readonly IRepository<KlantModel> _repo;
        private readonly DataContext _context;
        private readonly IMapper _mapper;
        public KlantController(IRepository<KlantModel> repo, IMapper mapper, DataContext context )
        {
            _repo = repo;
            _mapper = mapper;
            _context = context;
        }

        [HttpPut("{id}")]
        public async Task<ActionResult<KlantModel>> UpdateService( int id,  [FromBody]KlantModel klant)
        {
            Console.WriteLine("Update Service Method Invoked");

            Console.WriteLine("KlantId: " + klant.KlantId + " Klant-Bedrijfsnaam: "  + klant.Bedrijfsnaam);
            Console.WriteLine("Id: " + id);


            if (id != klant.KlantId)
            {
                return BadRequest("klant object is null");
            }

            if (!ModelState.IsValid)
            {
                return BadRequest("Invalid model object");
            }

            var uptklant = await _repo.GetDataById(id);

            Console.WriteLine("ToUpdate-Id: " + uptklant.KlantId + " ToUpdate-Bedrijfsnaam: "  + uptklant.Bedrijfsnaam );

            if (uptklant is null)
            {
                return NotFound();
            }

            _mapper.Map(klant, uptklant);
            await _repo.UpdateData(uptklant);
            return Ok(klant);
        }
    }
}

KlantRepository

namespace fixit.Data
{
    public class KlantRepository: IRepository<KlantModel>
    {
        private readonly DataContext _context;
        public KlantRepository(DataContext context)
        {
            _context = context;
        }

        public async Task<KlantModel> UpdateData(KlantModel klant)
        {
            _context.Update(klant).Property(x => x.KlantId).IsModified = false;

            Console.WriteLine("ToUpdate-Id-Repository: " + klant.KlantId + " ToUpdate-Bedrijfsnaam-Repository: "  + klant.Bedrijfsnaam );

            await _context.SaveChangesAsync();

            return klant;
        }
    }
}

KlantModel

namespace fixit.Models
{
    public class KlantModel
    {
        [Key]
        public int KlantId { get; set; }
        [Required]
        public string Mailaddres { get; set; }
        [Required]
        public string Wachtwoord { get; set; }
        [Required]
        public string Klantvoornaam { get; set; }
        [Required]
        public string Tussenvoegsel { get; set; }
        [Required]
        public string Klantachternaam { get; set; }
        [Required]
        public string Bedrijfsnaam { get; set; }
        [Required]
        public string Telefoonnummer { get; set; }
    }
}

----------------- ! update ! -----------------

It appeared the update did work but I didn't update the value because I didn't gave the new value.

updated the code in KlantController:

From this: await _repo.UpdateData(uptklant);

To this: await _repo.UpdateData(klant);

But now I get a new error:

Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware1 An unhandled exception has occurred while executing the request.
System.InvalidOperationException: The instance of entity type 'KlantModel' cannot be tracked because another instance with the same key value for {'KlantId'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

The new error gets stuck at this line of code From KlantRepository: _context.Update(klant).Property(x => x.KlantId).IsModified = false;

Answer 1

The Update worked good. What i forgot was to change the value that needed to be updated.

This is what i added to KlantController:

    uptklant.Mailaddres = klant.Mailaddres;
    uptklant.Wachtwoord = klant.Wachtwoord;
    uptklant.Klantvoornaam = klant.Klantvoornaam;
    uptklant.Tussenvoegsel = klant.Tussenvoegsel;
    uptklant.Klantachternaam = klant.Klantachternaam;
    uptklant.Bedrijfsnaam = klant.Bedrijfsnaam;
    uptklant.Telefoonnummer =klant.Telefoonnummer;

Full code:

namespace Controllers
{
    [ApiController]
    [Route("api/Klant")]
    [Produces("application/json")]
    public class KlantController : ControllerBase
    {

        private readonly IRepository<KlantModel> _repo;
        private readonly DataContext _context;
        private readonly IMapper _mapper;
        public KlantController(IRepository<KlantModel> repo, IMapper mapper, DataContext context )
        {
            _repo = repo;
            _mapper = mapper;
            _context = context;
        }

        [HttpPut("{id}")]
        public async Task<ActionResult<KlantModel>> UpdateService( int id,  [FromBody]KlantModel klant)
        {
            Console.WriteLine("Update Service Method Invoked");

            Console.WriteLine("KlantId: " + klant.KlantId + " Klant-Bedrijfsnaam: "  + klant.Bedrijfsnaam);
            Console.WriteLine("Id: " + id);


            if (id != klant.KlantId)
            {
                return BadRequest("klant object is null");
            }

            if (!ModelState.IsValid)
            {
                return BadRequest("Invalid model object");
            }

            var uptklant = await _repo.GetDataById(id);

            Console.WriteLine("ToUpdate-Id: " + uptklant.KlantId + " ToUpdate-Bedrijfsnaam: "  + uptklant.Bedrijfsnaam );

            if (uptklant is null)
            {
                return NotFound();
            }

            _mapper.Map(klant, uptklant);

            uptklant.Mailaddres = klant.Mailaddres;
            uptklant.Wachtwoord = klant.Wachtwoord;
            uptklant.Klantvoornaam = klant.Klantvoornaam;
            uptklant.Tussenvoegsel = klant.Tussenvoegsel;
            uptklant.Klantachternaam = klant.Klantachternaam;
            uptklant.Bedrijfsnaam = klant.Bedrijfsnaam;
            uptklant.Telefoonnummer =klant.Telefoonnummer;

            await _repo.UpdateData(uptklant);
            return Ok(klant);
        }
    }
}