internal static Expression DaysBetween12Attendance( ParameterExpression parm, CMSDataContext Db, int? lookback, int? progid, int? divid, int? org, CompareType op, int days) { Expression<Func<Person, int>> pred = p => Db.DaysBetween12Attend(p.PeopleId, progid, divid, org, lookback).Value; Expression left = Expression.Invoke(pred, parm); var right = Expression.Convert(Expression.Constant(days), left.Type); return Compare(left, op, right); }