SqlException: An expression of non-boolean type specified in a context where a condition is expected, near ')'

Unable to cast object of type 'System.Linq.Expressions.FieldExpression' to type 'System.Linq.Expressions.ParameterExpression

You should try calling ...Include... method in the ...DbSet... that you want to load the related entity:... var table = (from pc in _db.PlayerComments.Include(p => p.Period) //... ...And I think your query would be simpler if you use navigation properties instead explicit joins:...var table =await _db.PlayerComments.Include(p => p.Per...

Could not parse expression '…: The given arguments did not match the expected arguments”

Try breaking it down....Start from a simple test-case (like some dummy ...new UserResponseDTO...), then try with a simple static select (select one specific user), then add the if/else condition and try with and without ...conditions..., then add a simple static select to your first if/else branch, then do the same to the second branch, until you g...

Expression<Func<T, bool>> is not working as expected in mock setup

The problem with your setup is that you set ...GetEntities... to always return the full ...fakeLessonList... list. You never run in against the queries provided as arguments. ...To do this, you can use another overload of the Moq ...Returns()... method which provides the arguments passed by the caller via lambda method. Also, there's no need to moc...

Unable to cast object of type 'System.Linq.Expressions.MethodCallExpression' to type 'System.Linq.Expressions.LambdaExpression'

You can assign a variable for ..._ratingsProvider.GetRating... first, to avoid the error in the title....After that you will have another error saying entity framework does not support your query. You need something like LINQKit ...https://github.com/scottksmith95/LINQKit.... ...AsExpandable()... and ...Invoke(x, id)... are from LINQKit....using Li...

Cannot convert lambda expression to type "DbContextOptions <DataContext>" because it is not a delegate type

When creating your ...DataContext... class the parameter does not match what you defined in the ...DataContext... constructor. It expects an object of type ...DbContextOptions<DataContext>... But you are providing an action with an options parameter ...options => options.UseSqlServer("Data Source=.\\SQLEXPRESS;Initial Catalog=ProjAppTest;Integrated...

EF Core SQL Function LIKE Method with Linq Expression not working for Non String types

The "double cast" ...(string)(object)e.IntCol... is a way to trick the C# compiler to "pass" ...int... argument to a method expecting ...string... parameter (like ...EF.Functions.Like...). Of course if the method is actually called, you'll get invalid cast exception at runtime....But the trick works because methods like this are never "called", but...

EF core exception System.ArgumentException:Argument types do not match System.Linq.Expressions.Expression.Condition(Expression test, Expression ....)

I guess the issue is foreign key is not properly set in the CustomerBillTo entity. Just double check you have done it correctly as bellow....public class CustomerBillTo { [Required] [ForeignKey("Customer")] public string CustomerId { get; set; } public virtual Customer Customer { get; set; } } ...Also since your are accessing as ....

How to resolve casting Error in DB2 Boolean to .NET Core Boolean?

I solved it by simply not using a boolean but an integer. It's not ideal since it requires different handling later on in the code, but it works that way. ...public class ErrorView { [Required] public string Key { get; set; } public int Error { get; set; } }

assign null value to ifFalse parameter of Expression.Condition throws type mismatch exception

So I figured it out based on a reply from @Ivan Stoev. ...Instead of passing ...Expression.Constant(null,typeof(string))... as defaultvalue (and thus is the first ...ifFalse... parameter) I pass in ...Expression.Condition(Expression.Constant(false), defaultValue, defaultValue);...This nicely turns into ...NULL...:...""SELECT COALESCE(CASE WHEN...

Why only primitive types or enumeration types are supported in this context using EF?

You can't join a database table with an in-memory collection (in your case, ...List...):...Unable to create a constant value of type Only primitive types or enumeration types are supported in this context...You're converting these to in-memory collections by calling ...ToList...:... var groups = _repositoryGroup.GetAll().OrderBy(o => o.ID) ...