How to use a DbFunction to return an IQueryable?

[shaulbehr]

I have a Postgresql function with signature:

create or replace function my_table_func(enddate timestamptz)
	returns setof my_table

In my DbContext I have declared:

        [DbFunction("my_table_func")]
        public static IQueryable<MyTable> MyTableFunc(DateTime? endDate = null)
        {
            throw new Exception("Not implemented in code; this is a DB function.");
        }

When I try to generate an EF Migration, though, I get the following error:

System.InvalidOperationException: The DbFunction 'MyDbContext.MyTableFunc' has an invalid return type 'IQueryable<MyTable>'. Ensure that the return type can be mapped by the current provider.

Is it possible to create a DbMapping that I can use as an IQueryable<>?

I am using EF Core 2.1.4

[smitpatel]

Duplicate of #4319

It is not possible to use them in EFCore 2.x releases.