轉：SQL Server的自訂函數：統計兩日期之間工作日的數量

CREATE FUNCTION kmes.WorkDay_f(@dt_begin   datetime,@dt_end     datetime)RETURNS intASBEGIN    DECLARE @workday int,@i int,@bz bit,@dt datetime    set @dt_begin = convert(datetime, convert(nvarchar(32), @dt_begin, 23))    set @dt_end = convert(datetime, convert(nvarchar(32), @dt_end, 23))    IF @dt_begin>@dt_end        SELECT @bz=1,@dt=@dt_begin,@dt_begin=@dt_end,@dt_end=@dt    ELSE        SET @bz=0    SELECT @i=DATEDIFF(Day,@dt_begin,@dt_end),@workday=@i/7*5,@dt_begin=DATEADD(Day,@i/7*7,@dt_begin)    WHILE @dt_begin<@dt_end    BEGIN        SELECT @workday=CASE WHEN (@@DATEFIRST+DATEPART(Weekday,@dt_begin)-1)%7 BETWEEN 1 AND 5 THEN @workday+1 ELSE @workday END,@dt_begin=@dt_begin+1    END    RETURN(CASE WHEN @bz=1 THEN -@workday ELSE @workday END)ENDGO