2.5.4 计算工作时间的函数.sql

 if exists (select * from dbo.sysobjects where id = object_id(N'[tb_worktime]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [tb_worktime]
GO

--定义工作时间表
CREATE TABLE tb_worktime(
 ID       int identity(1,1) PRIMARY KEY,            --序号
 time_start smalldatetime,                            --工作的开始时间
 time_end  smalldatetime,                           --工作的结束时间
 worktime  AS DATEDIFF(Minute,time_start,time_end)  --工作时数(分钟)
)
GO

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_WorkTime]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_WorkTime]
GO

--计算两个日期之间的工作时间
CREATE FUNCTION f_WorkTime(
@date_begin datetime,  --计算的开始时间
@date_end datetime     --计算的结束时间
)RETURNS int
AS
BEGIN
 DECLARE @worktime int
 IF DATEDIFF(Day,@date_begin,@date_end)=0
  SELECT @worktime=SUM(DATEDIFF(Minute,
   CASE WHEN CONVERT(VARCHAR,@date_begin,108)>time_start
    THEN CONVERT(VARCHAR,@date_begin,108)
    ELSE time_start END,
   CASE WHEN CONVERT(VARCHAR,@date_end,108)    THEN CONVERT(VARCHAR,@date_end,108)
    ELSE time_end END))
  FROM tb_worktime
  WHERE time_end>CONVERT(VARCHAR,@date_begin,108)
   AND time_start ELSE
  SET @worktime
   =(SELECT SUM(CASE
     WHEN CONVERT(VARCHAR,@date_begin,108)>time_start
     THEN DATEDIFF(Minute,CONVERT(VARCHAR,@date_begin,108),time_end)
     ELSE worktime END)
    FROM tb_worktime
    WHERE time_end>CONVERT(VARCHAR,@date_begin,108))
   +(SELECT SUM(CASE
     WHEN CONVERT(VARCHAR,@date_end,108)     THEN DATEDIFF(Minute,time_start,CONVERT(VARCHAR,@date_end,108))
     ELSE worktime END)
    FROM tb_worktime
    WHERE time_start   +CASE
    WHEN DATEDIFF(Day,@date_begin,@date_end)>1
    THEN (DATEDIFF(Day,@date_begin,@date_end)-1)
     *(SELECT SUM(worktime) FROM tb_worktime)
    ELSE 0 END
 RETURN(@worktime)
END