Question

我正在尝试创建一个表单，该表单将从数据库中获取考勤数据并传输到Excel工作表进行打印。

我已经创建了这个表单并且有两个datetimepickers我已经设法让这个月开始旅行索赔以及我想要声明的月份。

我正在努力将其分成单个月，以便我可以利用个别月份来调查数据库。

到目前为止我已经

了

    if (TodateTimePicker.Value.Date <= FromdateTimePicker.Value.Date)
    {
        MessageBox.Show("End Date must be after Start Date");
    }
    else
    {
        fromDate = FromdateTimePicker.Value.Date;
        toDate = TodateTimePicker.Value.Date;

        fromDate = (fromDate.AddDays(1 - fromDate.Day));

        toDate = (toDate.AddDays(1 - toDate.Day)).AddMonths(1).AddDays(-1)
    }

我也有我想要使用的数据库命令

            com = new OleDbCommand("SELECT count(*), FROM Attendances WHERE year([Attendance_Date]) = ? GROUP BY [Person] ORDER BY count(*) DESC", Program.DB_CONNECTION);
            com.Parameters.Add(new OleDbParameter("", month));
            com.Parameters.Add(new OleDbParameter("", p.ID));

我真正的问题是如何获得每个月的第1个月以及所选择的两个日期之间每个月的最后日期？

Answer 1

以下是我找到的两种最简单的方法：

private int IntervalInMonthsBetweenDates(DateTime date1, DateTime date2)
{
    return date2.Subtract(date1).Days / 30;
}


private int IntervalInMonthsBetweenDates(DateTime date1, DateTime date2)
{
    return ((date1.Year - date2.Year) * 12) + date1.Month - date2.Month;
}

Answer 2

如果您想要在DateTime的年份和月份之间获得DateTimes的序列，其中每个月的开头和月末都会显示，那么您可以执行以下操作。

public static IEnumerable<DateTime> BeginEndOfEachMonthBetween(DateTime from, DateTime to)
{
    DateTime start = from.AddDays(1 - from.Day);
    while(start <= to)
    {
        yield return start;
        yield return start.AddMonths(1).AddDays(-1);
        start.AddMonths(1);
    }
}

但是看看你打算如何使用它会有所帮助。

听起来您可能想要一个与此类似的查询

SELECT 
    DatePart(year,Attendance_Date) As Year, 
    DatePart(month,Attendance_Date) As Month, 
    Count(*) As Attendance
FROM Attendances 
WHERE Attendance_Date Between @BeginDate And @EndDate
GROUP BY 
    DatePart(year,Attendance_Date), 
    DatePart(month,Attendance_Date)

Answer 3

我想出了一个解决方案，我计算了两个日期之间的月数，然后通过一个循环来增加开始日期的月数，以便给出两个月之间的每个月的第一天和最后一天原始日期，可能不是最好的方式，但它完全按照我的计划运作。

int months =（（toDate.Year - fromDate.Year）* 12 + toDate.Month - fromDate.Month）+ 1; //在两个日期之间找到几个月的munber并添加一个

        DateTime dateofclaim = new DateTime(); // define dateofclame to a new date  

        for (int i = 0; i < months; i++) // for each month run the code below, this will first run the fromDate then add a month until it gets to the toDate
        {
            dateofclaim = fromDate.AddMonths(i); // add one month to the start date

            claimfromDate = (dateofclaim.AddDays(1 - dateofclaim.Day)); // calculate the first date of the month

            claimtoDate = (dateofclaim.AddDays(1 - dateofclaim.Day)).AddMonths(1).AddDays(-1); // calculate the last day of the month

            OleDbCommand com = new OleDbCommand("SELECT sum([sum]) FROM Attendance WHERE ([Attendance_Date]) >= ? AND ([Attendance_Date]) <= ? AND [Person] = ?", Program.DB_CONNECTION); // count the total attendances in the month
            com.Parameters.Add(new OleDbParameter("", claimfromDate));
            com.Parameters.Add(new OleDbParameter("", claimtoDate));
            com.Parameters.Add(new OleDbParameter("", person.ID));

            OleDbDataReader dr = com.ExecuteReader(); // start reader  

            if (dr.Read()) // if a result is returned
            {
                try
                {
                    int attendance = Convert.ToInt32(dr.GetDouble(0)); // this is how many attendances have been counted for the selected month

                    ws.get_Range("B" + row.ToString()).Value2 = dateofclaim.ToString("MMM yyyy"); // print the Month of the clame into Colum B and row 83 then adding one for each following month
                    ws.get_Range("I" + row.ToString()).Value2 = attendance.ToString(); // print the number of attendances into Colum B and the respective row
                    row++; // add one to the row so next time this runs the data will be on the next row 
                }
                catch // if nothing as returned from the database then add the month and 0 in the attendance colum
                {
                    ws.get_Range("B" + row.ToString()).Value2 = dateofclaim.ToString("MMM yyyy");
                    ws.get_Range("I" + row.ToString()).Value2 = "0";
                    row++;
                }
            }
            dr.Close(); // close the database reader
        }

Answer 4

for (DateTime i = fromDate; i.Date <= toDate.Date; i = i.AddMonths(1))
        {
            Console.WriteLine(i.Month);
        }

选择两个日期之间的月份

4 个答案: