一些关于c#与Sql的时间的操作

DateTime beginDateTime = DateTime.Now.Date;
DateTime endDateTime = beginDateTime;
beginDateTime = beginDateTime.AddDays(-(int)beginDateTime.DayOfWeek); //得到周的开始时间
endDateTime = beginDateTime.AddDays(6); //得到周的结束时间
beginDateTime = new DateTime(beginDateTime.Year,beginDateTime.Month,1); //得到月的开始时间
endDateTime = beginDateTime.AddMonths(1).AddDays(-1); //得到月的结束时间

DECLARE @BeginDateTime DateTime
SELECT @BeginDateTime = dateadd(DAY,1-DATEPART(WEEKDAY,GETDATE()),GETDATE())
SELECT CONVERT(VARCHAR(20),@BeginDateTime,23) AS WeekBeginDateTime,CONVERT(VARCHAR(20),DATEADD(DAY,6,@BeginDateTime),23) AS WeekEndDateTime
SELECT CONVERT(VARCHAR(20),DATEADD(DAY,-DATEPART(DAY,GETDATE())+1,GETDATE()),23) AS MonthBeginDateTime,CONVERT(VARCHAR(20),DATEADD(MONTH,1,DATEADD(DAY,-DATEPART(DAY,GETDATE())+1,GETDATE())),23) AS MonthEndDateTime