LINQ - Contains with anonymous type

c#, linq, sql

Solution

In order to use Contains you must pass an instance of the type in the `IEnumerable<T>`. This is exceedingly hard with anonymous types.

Instead I would use the `Any` extension method overload which allows you to specify a comparison lambda. For example

var rows2 = (from t2 in db.TABLE2
    where (rows1.Any(x => x.COLUMN_B == t2.COLUMN_A))
    select t2;

Problem

When using this code (simplified for asking): ``` var rows1 = (from t1 in db.TABLE1 where (t1.COLUMN_A == 1) select new { t1.COLUMN_B, t1.COLUMN_C }); var rows2 = (from t2 in db.TABLE2 where (rows1.Contains(t2.COLUMN_A)) select t2; ``` I got the following error: The type arguments for method 'System.Linq.Enumerable.Contains(System.Collections.Generic.IEnumerable, TSource)' cannot be inferred from the usage. Try specifying the type arguments explicitly. I need to filter the first result by COLUMN_B, but I don't know how. Is there a way to filter it?

Original source