I have this deleted method and error occurs on the highlighted line and I don't know what to do.
[HttpDelete("{id}")]
public async Task<ActionResult<Producto>> DeleteProducto(int id)
{
var producto = await _context.Productos.FindAsync(id);
_context.Productos.Remove(producto);
await _context.SaveChangesAsync();
producto = await _context.Productos.AsQueryable<Producto>().LastOrDefaultAsync();
if (producto == null)
{
producto = new Producto();
}
return producto;
}
The responseText:
api/Productos/5:1 Failed to load resource: the server responded with a status of 500 ()
api/Productos/5:1 Failed to load resource: the server responded with a status of 500 ()
config:1773 System.ArgumentNullException: Value cannot be null. (Parameter 'entity')
at Microsoft.EntityFrameworkCore.Utilities.Check.NotNull[T](T value, String parameterName)
at Microsoft.EntityFrameworkCore.DbContext.Remove[TEntity](TEntity entity)
at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.Remove(TEntity entity)
at Tienda.Controllers.ProductosController.DeleteProducto(Int32 id) in D:\Documents\Visual Studio 2019\Projects\DesarrolloWeb\Tienda\Controllers\ProductosController.cs:line 117
at lambda_method(Closure , Object )
at Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_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>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
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.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
HEADERS
=======
Accept: */*
Accept-Encoding: gzip, deflate, br
Accept-Language: es,es-ES;q=0.9,en;q=0.8,en-GB;q=0.7,en-US;q=0.6
Cache-Control: no-cache
Connection: close
Cookie: UltIdProducto=5; .AspNetCore.Antiforgery.kpkyKqXb3cQ=CfDJ8Pd8cRKWTcdNqVzVVvXtmByBhwBwC1e5j0Nm0rpHDkviQKFjLqKMj_BhXoTj-XjON9dgl4876nDaJe4gG7cma1mwETlF2R6xda8N6JjdrSqDowe-rRhtTfv5Iz62QCn2jX5AlF0hbiXJuzHh9tsxvdk
Host: localhost:44374
Pragma: no-cache
Referer: https://localhost:44374/config
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36 Edg/83.0.478.64
x-requested-with: XMLHttpRequest
origin: https://localhost:44374
sec-fetch-site: same-origin
sec-fetch-mode: cors
sec-fetch-dest: empty
So Remove complains about being called with a null entity.
FindAsync can return null if the id key doesn't match. As it seems to always happen, more likely you are not passing the id correctly. Check this is the expected value rather than maybe 0 ?
If it's rare (or once you fixed the initial issue) you still my want to handle that in your code, for example in case someone would try to delete an entity that was just deleted by someone else.
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Member
1 Points
7 Posts
Internal server error after deleting record and trying to retrieve last record
Jul 15, 2020 11:52 AM|FedericoLuna|LINK
Best regards.
I have this deleted method and error occurs on the highlighted line and I don't know what to do.
[HttpDelete("{id}")] public async Task<ActionResult<Producto>> DeleteProducto(int id) { var producto = await _context.Productos.FindAsync(id); _context.Productos.Remove(producto); await _context.SaveChangesAsync(); producto = await _context.Productos.AsQueryable<Producto>().LastOrDefaultAsync(); if (producto == null) { producto = new Producto(); } return producto; }The responseText:
All-Star
48490 Points
18071 Posts
Re: Internal server error after deleting record and trying to retrieve last record
Jul 15, 2020 12:02 PM|PatriceSc|LINK
Hi,
So Remove complains about being called with a null entity.
FindAsync can return null if the id key doesn't match. As it seems to always happen, more likely you are not passing the id correctly. Check this is the expected value rather than maybe 0 ?
If it's rare (or once you fixed the initial issue) you still my want to handle that in your code, for example in case someone would try to delete an entity that was just deleted by someone else.
Member
70 Points
22 Posts
Re: Internal server error after deleting record and trying to retrieve last record
Jul 16, 2020 02:51 AM|yinqiu|LINK
Hi，FedericoLuna
From the error returned, you should not have the correct id.
Try this code:
[HttpPost, ActionName("Delete")] public async Task<ActionResult<Producto>> DeleteProducto(int id){ var producto = await _context.Productos.FindAsync(id); _context.Productos.Remove(producto); await _context.SaveChangesAsync(); producto = await _context.Productos.AsQueryable<Producto>().LastOrDefaultAsync(); if (producto == null) { producto = new Producto(); } return producto; } }
I would like to ask if you are using EFCore 3.X.If it is, then your LastOrDefaultAsync() method will not work properly.
This is a new one after EFCore3.0 Features, you can take a look at this:
https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-3.0/breaking-changes?view=aspnetcore-1.1#linq-queries-are-no-longer-evaluated-on-the-client
Hope this can help you
Best Regards
yinqiu