Question

有两个表Leaves, Attendanceatd包含数据。

我需要在这两个表格中显示不同的ListofDates和employeeid，其条件是在离开表 approvalstatus ='已批准' 中表格日期列上的 startdate / enddate 期限持续时间。

表架构： SQL FIDDLE

create table Leaves(idemp_lv int,leavedate Datetime, approvalstatus varchar(100))
    insert into Leaves values (1,'2013-04-22 00:00:00.000','Approved');
    insert into Leaves values (2,'2013-04-21 00:00:00.000','Approved'); 
    insert into Leaves values(3,'2013-04-26 00:00:00.000','Approved');
    insert into Leaves values(1,'2013-04-21 00:00:00.000','Pending'); 
    insert into Leaves values(3,'2013-04-02 00:00:00.000','Pending');
    insert into Leaves values(1,'2013-04-19 00:00:00.000','Approved');

create table Attendanceatd(idemp_at int,absentdate Datetime)
insert into Attendanceatd values(1,'2013-04-19 00:00:00.000');
insert into Attendanceatd values(3,'2013-04-02 00:00:00.000');
insert into Attendanceatd values(1,'2013-04-15 00:00:00.000');

期望的输出：

Empid ListofDate
1     2013-04-22 00:00:00.000
1     2013-04-19 00:00:00.000
1     2013-04-15 00:00:00.000
2     2013-04-21 00:00:00.000
3     2013-04-26 00:00:00.000
3     2013-04-02 00:00:00.000

目前我正在尝试这个：

select ListOfDates
from 
(
 select leavedate as ListOfDates from leaves where approvalstatus='Approved' and leavedate >='20130302' and  leavedate <'20130501'
 union
 select absentdate  as ListOfDates from Attendanceatd where  absentdate >='20130302' and  absentdate <'20130501'
)t1
group by ListOfDates

无法与 ListOfDates一起 employeeId

Answer 1

我认为你不需要分组。这给了你想要的东西

 select idemp_lv, leavedate as ListOfDates
 from leaves
 where approvalstatus='Approved' and leavedate >='20130302' and  leavedate <'20130501'
 union
 select idemp_at, absentdate  as ListOfDates
 from Attendanceatd
 where  absentdate >='20130302' and  absentdate <'20130501'

自动UNION applies DISTINCT（注意使用UNION ALL时的区别）

Updated SQLFiddle

Answer 2

select distinct empid, ListOfDates
from 
(
 select idemp_lv as empid, leavedate as ListOfDates from leaves where approvalstatus='Approved' and leavedate >='20130302' and  leavedate <'20130501'
 union all
 select idemp_at as empid, absentdate  as ListOfDates from Attendanceatd where  absentdate >='20130302' and  absentdate <'20130501'
)t1
group by empid, ListOfDates

除非我遗漏了某些东西，否则应该这样做。请记住，union all会更快，但会导致更加麻烦的sql排序。始终执行执行计划以检查性能。

Answer 3

select EmpId,ListOfDates
from 
(
select idemp_lv as EmpId ,leavedate as ListOfDates from leaves where approvalstatus='Approved' 
union all
select idemp_at as EmpId , absentdate  as ListOfDates from Attendanceatd
)T1
where ListOfDates between '2013-03-02' and '2013-05-01'
group by  EmpId,ListOfDates

如何从两个不同的表列SQL Server中获取一个不同的ListofDate列

3 个答案: