Query

gistfile1.txt

void Main()
{
	IDb db;
	
	new PersonNameProjection(
		new PersonQuery(db.Table<Person>()).ByName("Tod")
	).Execute();
		
	
}

public interface IDb
{
	IQueryable<T> Table<T>();
}

public class Query<T, TQuery> where TQuery : Query<T,TQuery>
{
	IEnumerable<T> _query;
	
	public Query(IQueryable<T> query)
	{
		_query = query;
	}
	
	protected TQuery Where(Func<T,bool> clause)
	{
		_query = _query.Where (clause);
		return (TQuery) this;
	}
	
	public IEnumerable<T> Query
	{
		get{
			return _query;
		}
	}
	
	public IReadOnlyList<T> Execute()
	{
		 return _query.ToArray();
	}
	
}

public class Person
{
	public string Name { get; set;}
}

public class PersonQuery : Query<Person, PersonQuery>
{
	public PersonQuery(IQueryable<Person> query) : base(query)
	{
	}

	public PersonQuery ByName(string name)
	{
		return Where(p => p.Name == name);
	}
}

public class PersonNameProjection
{
	private PersonQuery _query
	
	public PersonNameProjection(PersonQuery query)
	{
		_query = query;
	}
	
	public string[] Execute()
	{
		return _query.Query.Select(p => p.Name);
	}
}