Send Http Get request to a web api

Occasional Visitor

I am trying to send a get request to my web api project:

[HttpGet]
public async Task<IActionResult> GetArtists()
{
var artists = await (from artist in _dbContext.Artists
select new
{
Id = artist.Id,
Name = artist.Name,
ImageUrl = artist.ImageUrl,
}).ToListAsync();

return Ok(artists);
}

And it showing an error message:

System.TypeInitializationException: The type initializer for 'Microsoft.EntityFrameworkCore.Query.QueryableMethods' threw an exception.
---> System.InvalidOperationException: Sequence contains more than one matching element
at System.Linq.ThrowHelper.ThrowMoreThanOneMatchException()
at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source, Func`2 predicate)
at Microsoft.EntityFrameworkCore.Query.QueryableMethods..cctor()
--- End of inner exception stack trace ---
at Microsoft.EntityFrameworkCore.Query.Internal.QueryableMethodNormalizingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
at Microsoft.EntityFrameworkCore.Query.RelationalQueryTranslationPreprocessor.NormalizeQueryableMethod(Expression expression)
at Microsoft.EntityFrameworkCore.Query.QueryTranslationPreprocessor.Process(Expression query)
at Microsoft.EntityFrameworkCore.Query.RelationalQueryTranslationPreprocessor.Process(Expression query)
at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass12_0`1.<ExecuteAsync>b__0()
at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)


Please help me out.

2 Replies

@Micheal_Hastrup 

This is the way i would do.

 

These type of questions should be done in Microsoft Q&A.

 

[HttpGet]
public async Task<IActionResult> GetArtists()
{
var artists =await _dbContext.Artists.ToListAsync();
return Ok(artists);
}

 

Hi @Micheal_Hastrup,

Thanks for posting your issue here.

However this platform is used for how-to discussions and sharing best practices for building any app with .NET.Since your issue is a technical question, welcome to post it in Microsoft Q&A forum, the support team and communities on Microsoft Q&A will help you for any technical questions.
Besides, it will be appreciated if you can share it here once you post this technical question Microsoft Q&A.
Best Regards,
Lan Huang