Exception: NullReferenceException when using .Where(x => x.Field.Contains(txt))

[luca-esse]

The following query throws a NullReferenceException: Context.Games.Where(x => x.Name.Contains(searchText)).ToListAsync();

The problems seems to be the string.Contains() method.

EntityFramework-Classic version: 7.0.24

Here is the stack trace:

System.NullReferenceException: Object reference not set to an instance of an object. at System.Linq.Expressions.Compiler.LambdaCompiler.EmitMethodCall(Expression obj, MethodInfo method, IArgumentProvider methodCallExpr, CompilationFlags flags) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitInvocationExpression(Expression expr, CompilationFlags flags) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitExpression(Expression node, CompilationFlags flags) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitInstance(Expression instance, Type& type) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitMemberExpression(Expression expr) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitExpression(Expression node, CompilationFlags flags) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitLambdaBody(CompilerScope parent, Boolean inlined, CompilationFlags flags) at System.Linq.Expressions.Compiler.LambdaCompiler.EmitLambdaBody() at System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda) at System.Data.Entity.Core.Objects.ELinq.QueryParameterExpression.EvaluateParameter(Object[] arguments) at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable1 forMergeOption) at System.Data.Entity.Core.Objects.ObjectQuery1.<>c__DisplayClass43_0.b__1() at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransactionAsync[T](Func1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess, CancellationToken cancellationToken) at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.ExecuteAsyncImplementation[TResult](Func1 func) at System.Data.Entity.Core.Objects.ObjectQuery1.GetResultsAsync(Nullable1 forMergeOption, IDbExecutionStrategy executionStrategy, CancellationToken cancellationToken) at System.Data.Entity.Internal.LazyAsyncEnumerator1.FirstMoveNextAsync(CancellationToken cancellationToken) at System.Data.Entity.Infrastructure.IDbAsyncEnumerableExtensions.SingleAsync[TSource](IDbAsyncEnumerable1 source, CancellationToken cancellationToken)

[JonathanMagnan]

Hello @luca-esse ,

We successfully reproduced that issue on NET Core, but it works perfectly on NET Framework.

That kind of issue normally happens when a method is no longer available in .NET Code.

It happens when the method tries to compile the current expression ( QueryParameterExpression (line: 65))

We will investigate it on Monday.

Best Regards,

Jonathan

[luca-esse]

Hi Jonathan, Do you have any update?

Best regards, Luca

[JonathanMagnan]

Hello @luca-esse ,

We passed a lot of time this week on this issue.

We can easily reproduce it, easily find out which line fail.

However, it's currently very hard to find out what's causing it as that happen when a compiled expression is executed.

We continue to investigate it but that one is currently harder to find that we initially though.

[JonathanMagnan]

Hello @luca-esse ,

Sorry for being so long, that one is not easy ;(

We finally made a good discovery today about the Expression used that cause the issue.

The expression work on .NET Framework but not on NET Core

[JonathanMagnan]

Hello @luca-esse ,

The v7.0.29 has been released.

Let me know if everything works as expected.

Best Regards,

Jonathan

[luca-esse]

Hello @JonathanMagnan

Can confirm it's working with the v7.0.29 :)

Best regards, Luca

[JonathanMagnan]

Great ;)