Entity Framework Self referencing loop detected for property 'context' ERROR single Model-CodePudding

I am getting this error on my single model webapi. All the answers I found on this error results on cycle loops between related tables but my project has one table alone.

This is the complete error. I tried with the default Json library but I have installed the Newtonsoft.Json and getting the same error.

I am using .NET 6 and InMemoryDatabase.

Newtonsoft.Json.JsonSerializationException: Self referencing loop detected for property 'context' with type 'NumsAndOps.Data.NumsAndOpsDbContext'. Path 'context.changeTracker'.
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CheckForCircularReference(JsonWriter writer, Object value, JsonProperty property, JsonContract contract, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues(JsonWriter writer, Object value, JsonContainerContract contract, JsonProperty member, JsonProperty property, JsonContract& memberContract, Object& memberValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Serialize(JsonWriter jsonWriter, Object value)
   at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
   at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
   at Microsoft.AspNetCore.Mvc.Formatters.NewtonsoftJsonOutputFormatter.WriteResponseBodyAsync(OutputFormatterWriteContext context, Encoding selectedEncoding)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|30_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

HEADERS
=======
Accept: */*
Host: localhost:7060
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.61 Safari/537.36
:method: POST
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9
Content-Type: application/json-patch json
Origin: https://localhost:7060
Referer: https://localhost:7060/swagger/index.html
Content-Length: 280
sec-gpc: 1
sec-fetch-site: same-origin
sec-fetch-mode: cors
sec-fetch-dest: empty

This is my model. I have changed Id between Guid, string, int and nothing. The same with the Score field.

public class User
{
    [Key]
    public int Id { get; set; }
    [Required]
    public string Username { get; set; };
    [Required, EmailAddress]
    public string Email { get; set; };
    public string? GoogleId { get; set; } = null!;
    public string? FacebookId { get; set; } = null!;
    public string? TwitterId { get; set; } = null!;
    public string? MicrosoftId { get; set; } = null!;
    [Required]
    public DateTime SignUpDate { get; set; } = DateTime.Now;
    [Required]
    public DateTime LastConnectionDate { get; set; } = DateTime.Now;
    [Required]
    public ulong Score { get; set; } = 0;
}

This is my context.

public class UserContext: DbContext
{
    public UserContext(DbContextOptions<UserContext> options)
        : base(options) { }

    public DbSet<User> Users { get; set; }
}

My controller.

[HttpPost("Post")]
    public IActionResult Post(User user)
    {
        var newUser = new User();
        newUser.Username = user.Username;
        newUser.FacebookId = user.FacebookId;
        newUser.MicrosoftId = user.MicrosoftId;
        newUser.TwitterId = user.TwitterId;
        newUser.GoogleId = user.GoogleId;
        newUser.Email = user.Email;
        newUser.Score = user.Score;

        var response = dbContext.Users.Add(newUser);

        return Ok(response);
    }

Thanks!

CodePudding user response：

Check the type of the response variable. You're probably getting an EntityEntry<User> back, see Add() docs. I doubt this is what you are expecting to send to the client.

Try:

var response = dbContext.Users.Add(newUser);
dbContext.SaveChanges()
return Ok(response.Entity);