在时间管理系统的sql查询中需要帮助

Question

我有两张桌子，一张是 EMployeeMaster，另一张是出勤

***EmployeeMaster***

EmployeeId    EmployeeName   DepartmentId
1             ABC            1
2             XYZ            2
3             PQR            2
4             WXY            1

现在我有另一张桌子考勤

***Attendance***

AttendanceId EmployeeId      Date                  InTime       OutTime
1            1            2011-04-04 00:00:00    10:00 AM     6:30 PM
2            2            2011-04-04 00:00:00    09:45 AM     7:10 PM

一旦员工进入办公室并将手指放在设备上，他的条目将进入考勤表，其中包含 InTime、EmployeeId 和 Date。

所以没有进入办公室的员工，他的条目将不存在于出勤表中。

现在我想生成每日报告..它应该按日期显示公司所有员工的出勤率以及他们的 Intime/outTime。 所有缺勤的员工也应显示在此报告中。

所以我想要：

EmployeeId    EMployeeName   DepartmentId  Date                 InTime    OutTime
1             ABC            1             2011-04-04 00:00:00  10:00 AM  6:30 PM
2             XYZ            2             2011-04-04 00:00:00  09:45 AM  7:10 PM
3             PQR            2             NULL/-               NULL/-    NULL/-
4             WXY            1             NULL/-               NULL/-    NULL/-

你能告诉我应该查询什么吗？？？

Answer 1

您应该使用左外连接。

declare @E table (EmployeeId int,    EmployeeName varchar(50),   DepartmentId int)
declare @A table (AttendanceId int, EmployeeId int, [Date] date, InTime time, OutTime time)

insert into @E values
(1,             'ABC',            1),
(2,             'XYZ',            2),
(3,             'PQR',            2),
(4,             'WXY',            1)

insert into @A values
(1,            1,            '2011-04-04 00:00:00',    '10:00 AM',     '6:30 PM'),
(2,            2,            '2011-04-04 00:00:00',    '09:45 AM',     '7:10 PM')

select
  E.EmployeeId,
  E.EmployeeName,
  E.DepartmentId,
  A.[Date],
  A.InTime,
  A.OutTime
from @E as E
  left outer join @A as A
    on E.EmployeeId = A.EmployeeId and
       A.[Date] = '2011-04-04 00:00:00'

结果

EmployeeId  EmployeeName                                       DepartmentId Date       InTime           OutTime
----------- -------------------------------------------------- ------------ ---------- ---------------- ----------------
1           ABC                                                1            2011-04-04 10:00:00.0000000 18:30:00.0000000
2           XYZ                                                2            2011-04-04 09:45:00.0000000 19:10:00.0000000
3           PQR                                                2            NULL       NULL             NULL
4           WXY                                                1            NULL       NULL             NULL

编辑 1

如果您需要这样做一个月，我会使用某种数字表或日历表。在这里，我使用 cte 使用 @FromDate 和 @ToDate 构建日历

declare @E table (EmployeeId int, EmployeeName varchar(15), DepartmentId int)
declare @A table (AttendanceId int, EmployeeId int, [Date] date, InTime time, OutTime time)

insert into @E values
(1, 'ABC', 1),
(2, 'XYZ', 2),
(3, 'PQR', 2),
(4, 'WXY', 1)

insert into @A values
(1, 1, '2011-04-02', '04:00 AM', '4:30 PM'),
(2, 2, '2011-04-02', '05:00 AM', '5:30 PM'),
(3, 1, '2011-04-03', '06:00 AM', '6:30 PM'),
(4, 2, '2011-04-03', '07:00 AM', '7:30 PM'),
(5, 1, '2011-04-04', '08:00 AM', '8:30 PM'),
(6, 2, '2011-04-05', '09:00 AM', '9:10 PM')

-- Set FromDate to first day of month
declare @FromDate date = '20110401'
-- Set ToDate to last day of month
declare @ToDate date = '20110405'

-- Create cte with all dates between FromDate and ToDate
;with cteCal as 
(
  select @FromDate as [Date]
  union all
  select dateadd(d, 1, [Date]) as [Date]
  from cteCal
  where [Date] < @ToDate
)
select
  E.EmployeeId,
  E.EmployeeName,
  E.DepartmentId,
  C.[Date],
  A.InTime,
  A.OutTime
from cteCal as C
  cross join @E as E
  left outer join @A as A
    on E.EmployeeId = A.EmployeeId and
       C.[Date] = A.[Date]
order by C.[Date], E.EmployeeName 
option (maxrecursion 0)

Answer 2

应该是这样的：

select 
  EmployeeId,
  EmployeeName,
  DepartmentId,
  Date,
  InTime,
  OutTime
from EmployeeMaster em
left join Attendance a on em.EmployeeId=a.EmployeeId and Date='2011-04-04 00:00:00'

Answer 3

select E.EmloyeeId, EmployeeName, DepartmentId, Date, InTime, OutTime
from   EmployeeMaster as e
       LEFT JOIN Attendance as a ON a.EmloyeeId = e.EmloyeeId