Question

我有两个表employee表和employee dependency表。员工就像下面这样。

insert into E values(1,'Adam')
insert into E values(2,'Bob')
insert into E values(3,'Candy')
insert into E values(4,'Doug')
insert into E values(5,'Earl')
insert into E values(6,'Fran')

员工依赖关系表如下所示

insert into Ed values(3,'2')
insert into Ed values(3,'5')
insert into Ed values(2,'1')
insert into Ed values(2,'4')
insert into Ed values(5,'6')

我需要找到如下的依赖列表

Eid  Ename     Dname
3     Candy    Bob,Fran

请帮助我找到上述内容。

Answer 1

设定：

create table E(id int , name varchar(100))

insert into E values(1,'Adam')
insert into E values(2,'Bob')
insert into E values(3,'Candy')
insert into E values(4,'Doug')
insert into E values(5,'Earl')
insert into E values(6,'Fran')

create table Ed(id1 int, id2 int)

insert into Ed values(3,2) 
insert into Ed values(3,5)
insert into Ed values(2,1)
insert into Ed values(2,4)
insert into Ed values(5,6)

查询：

select Name,
    stuff((select ',' + e1.name
    from Ed
        join E e1 on
            Ed.id2 = e1.id
    where Ed.id1 = E.id
    for xml path('')), 1, 1, '') as Dependents
from E

结果：

Name       Dependents
---------- --------------
Adam       NULL
Bob        Adam,Doug
Candy      Bob,Earl
Doug       NULL
Earl       Fran
Fran       NULL

如果您只需要展示那些有家属的人：

select *
from
(
    select Name,
        stuff((select ',' + e1.name
        from Ed
            join E e1 on
                Ed.id2 = e1.id
        where Ed.id1 = E.id
        for xml path('')), 1, 1, '') as Dependents
    from E
) tt
where Dependents is not null

帮我找到依赖列表

1 个答案: