Question

所以在我的人桌上...我有Id，Name＆amp; HolidaysRemaining。

它用于假日预订应用程序，并且当用户从日历中选择日期并单击按钮时，所选择的每个日期将存储在数据库中，我试图减去剩余1的假期，因为每个假期都是预订，但它似乎没有恢复。

//listHolidays in correct format dd/mm/yy
    [HttpPost]
    public ActionResult listHolidays(Holiday holiday, Person person , int? PersonId, string HolidayDate, string endDate, string AlreadyExists)
    {
        db.People.Attach(person);
        //int holidaysRemaining = 20;
        //person.HolidaysRemaining = holidaysRemaining;    

        DateTime startDates = Convert.ToDateTime(HolidayDate);
        DateTime endDates = Convert.ToDateTime(endDate);

    try{

        while (startDates <= endDates)
        {
            if (startDates.DayOfWeek != DayOfWeek.Saturday && startDates.DayOfWeek != DayOfWeek.Sunday)
            {                 
                //if user selects Holiday that already exists, wont add it to Db
                //gets string, and uses the previously converted to dateTime 'startDate'
                //id so only applies to person creating holidays
                ViewBag.CantDuplicateHolidays = String.IsNullOrEmpty(AlreadyExists) ? "date" : "";
                var dates = from d in db.Holidays
                where d.HolidayDate == startDates && d.PersonId == PersonId
                select d;

                // <= 0..so if holiday does not already exist
                if (dates.Count() <= 0)
                {
                  //  holidaysRemaining--;
                    person.HolidaysRemaining = person.HolidaysRemaining - 1;

                    Holiday holiday1 = new Holiday();
                    holiday1.PersonId = PersonId.Value;
                    holiday1.HolidayDate = startDates;

                    db.Holidays.AddObject(holiday1);


                    db.SaveChanges();
                    //say start date is 10. AddDays(1) will make it 11 then return it to startDates in 'startDates' = startdates,
                    //but doesnt chage the value of startdates = 'startdates'
                }

            }
        }

        startDates = startDates.AddDays(1);
    }


    finally
    {
        db.People.Detach();
    }

    return RedirectToAction("Index");
}

Answer 1

我认为你的问题在这里：

if (dates.Count() <= 0)
    {
    //  holidaysRemaining--;
    person.HolidaysRemaining--;

尝试将其更改为：

if (dates.Count() <= 0)
    {
    //  holidaysRemaining--;
    person.HolidaysRemaining = person.HolidaysRemaining - 1;

修改

此外，您从未真正用人更新数据库？

db.People.Attach(person);

之前db.SaveChanges();

再次编辑

试试这个：

[HttpPost] public ActionResult listHolidays（假日假日，Person person，int？PersonId，string HolidayDate，string endDate，string AlreadyExists） {
// int holidaysRemaining = 20; //person.HolidaysRemaining = holidaysRemaining;

DateTime startDates = Convert.ToDateTime(HolidayDate); DateTime endDates = Convert.ToDateTime(endDate); while (startDates <= endDates) { if (startDates.DayOfWeek != DayOfWeek.Saturday && startDates.DayOfWeek != DayOfWeek.Sunday) { //if user selects Holiday that already exists, wont add it to Db //gets string, and uses the previously converted to dateTime 'startDate' //id so only applies to person creating holidays ViewBag.CantDuplicateHolidays = String.IsNullOrEmpty(AlreadyExists) ? "date" : ""; var dates = from d in db.Holidays where d.HolidayDate == startDates && d.PersonId == PersonId select d; // <= 0..so if holiday does not already exist if (dates.Count() <= 0) { // holidaysRemaining--; person.HolidaysRemaining = person.HolidaysRemaining - 1; Holiday holiday1 = new Holiday(); holiday1.PersonId = PersonId.Value; holiday1.HolidayDate = startDates; db.Holidays.AddObject(holiday1); db.People.Attach(person); db.SaveChanges(); //say start date is 10. AddDays(1) will make it 11 then return it to startDates in 'startDates' = startdates, //but doesnt chage the value of startdates = 'startdates' } } startDates = startDates.AddDays(1); } return RedirectToAction("Index"); }

Answer 2

这可能是最简单的解决方案。

取代：

person.HolidaysRemaining = person.HolidaysRemaining - 1;

使用：

var dbPerson = from p in db.People where p.Id == PersonId select p;
dbPerson[0].HolidaysRemaining--;

或者我们讨论了附加人物对象，因为你拥有它：

    db.People.Attach(person)
    try {
        // ... loop and everything else here
    } finally {
        db.People.Detach(person);
    }
} // end of method

但这有点脆弱，只有在Person中还没有db.People对象时才有必要。

注意：将person和PersonId传递给listHolidays()似乎有点奇怪。

在行动之后获得一个减少的int

2 个答案: