Question

假设我有一组包含业务分析师，质量保证分析师等数据的角色表。所有都由唯一ID索引。我有另一个表，人们再次使用唯一的ID索引。

我为具有多个角色名为“PersonRole”的人创建了第三个表格。如果我想为具有业务分析师和开发人员角色的人（假设Id为2和3）查询PersonRole，我需要什么类型的查询？我应该使用子查询或联合构建它吗？

我试过这个，但没有回复。

select * from PersonRole 
inner join Person on Person.Id = PersonRole.PersonId
where Person.Id = 3
and PersonRole.RoleId = 2
and PersonRole.RoleId = 3

Answer 1

您可以使用OR

select * from PersonRole 
inner join Person on Person.Id = PersonRole.PersonId
where Person.Id = 3
and (PersonRole.RoleId = 2 OR PersonRole.RoleId = 3)

另外IN

select * from PersonRole 
inner join Person on Person.Id = PersonRole.PersonId
where Person.Id = 3
and PersonRole.RoleId IN (2,3)

Answer 2

试试这个：

select * from PersonRole 
inner join Person on Person.Id = PersonRole.PersonId
where Person.Id = 3
OR PersonRole.RoleId = 2 OR
PersonRole.RoleId = 3

OR

select * from PersonRole 
inner join Person on Person.Id = PersonRole.PersonId
where Person.Id = 3
OR PersonRole.RoleId IN (2 ,3)

Answer 3

如果要查询同时拥有这两种角色的人，我建议使用having子句进行聚合查询。这是写这个的一种方法：

select pr.PersonId
from PersonRole pr
group by pr.PersonId
having sum(case when pr.RoleId = 2 then 1 else 0 end) > 0 and
       sum(case when pr.RoleId = 3 then 1 else 0 end) > 0;

如果您需要Person表中的更多详细信息，可以将其加入。

Answer 4

或加入personRole两次，一次针对您想要的每个条件：

select p.* from 
Person p inner join
PersonRole r2 on 
p.Id = r2.PersonId and
r2.RoleId = 2 inner join
PersonRole r3 on 
p.Id = r3.PersonId and
r3.RoleId = 3
where 
p.Id = 3

如何查询表中的多个条件

4 个答案: