gistfile1.txt

    
    var columnSet = ColumnSetBuilder.Generate<msnfp_Transaction>(x => x.msnfp_TransactionId, x=>x.msnfp_Amount);
    var columnSet2 = ColumnSetBuilder.Generate<msnfp_Transaction>(x =>new { x.msnfp_TransactionId, x.msnfp_Amount });
    
    public static class ColumnSetBuilder
    {
        public static ColumnSet Generate<T>(params Expression<Func<T,object>>[] expressions)
        {
            
            return new ColumnSet(expressions.Select(k => ParseExpression(k)).ToArray());
        }
        public static ColumnSet Generate<T>(Expression<Func<T, object>> expression)
        {

            if(expression.Body is NewExpression newExpression)
            {
                return new ColumnSet(newExpression.Arguments.OfType<MemberExpression>().Select(m => m.Member.GetCustomAttributes<AttributeLogicalNameAttribute>().FirstOrDefault().LogicalName).ToArray());
            }
            if (expression.Body is UnaryExpression)
            {
                return new ColumnSet(ParseExpression(expression));
            }
            throw new NotImplementedException();
        }

        private static string ParseExpression<T>(Expression<Func<T, object>> k)
        {
            if (k.Body is UnaryExpression unary)
            {
                return (unary.Operand as MemberExpression).Member.GetCustomAttributes<AttributeLogicalNameAttribute>().FirstOrDefault().LogicalName;
            }
            throw new NotImplementedException();
           
        }


    }