Dynamic Expression using LINQ. How To Find the Kitchens?

Question

I try do implement a user dynamic filter, where used selects some properties, selects some operators and selects also the values.

As I didn\'t find yet an answer to

Answer 1

// ???????????????????????? DOES NOT WORK
var kitchens = houses.AsQueryable().Where(comparison);

The Where method takes a Func or a Expression> as the parameter, but the variable comparison is of type LambdaExpression, which doesn't match. You need to use another overload of the method:

var comparison = Expression.Lambda>(
                Expression.Equal(houseMainRoomTypeParam,
                Expression.Constant("Kitchen", typeof(RoomType))));
//now the type of comparison is Expression>

//the overload in Expression.cs
public static Expression Lambda(Expression body, params ParameterExpression[] parameters);