Доброго дня!

вот такой тест

        [Test]
        public void Union2()
        {
            ForEachProvider(db => AreEqual(
                from r in (from g in GrandChild join ch in Child on g.ChildID equals ch.ChildID select ch.ChildID).Union(
                (from ch in Child join p in Parent on ch.ParentID equals p.ParentID select ch.ChildID))
                join child in Child on r equals child.ChildID select child ,

                from r in (from g in db.GrandChild join ch in db.Child on g.ChildID equals ch.ChildID select ch.ChildID).Union(
                (from ch in db.Child join p in db.Parent on ch.ParentID equals p.ParentID select ch.ChildID))
                join child in db.Child on r equals child.ChildID select child));
        }

падает с Exception: BLToolkit.Data.Sql.SqlException: Table not found for 'BLToolkit.Data.Sql.SqlQuery+Column'.
BLToolkit.Data.Sql.SqlProvider.BasicSqlProvider.BuildExpression(StringBuilder sb, ISqlExpression expr, Boolean buildTableName, Boolean checkParentheses, String alias, Boolean& addAlias) in \bl-toolkit\Source\Data\Sql\SqlProvider\BasicSqlProvider.cs: line 1109

Посмотрел в код — не могу сообразить как поправить...