在SQL中合并两个查询

Question

基本上，我需要合并两个表中PSROLEUSER相等的两个查询的结果。 我该怎么做？

select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'NCC_Manag';
select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'HRM-Content Amin';

Answer 1

下面的查询假定ROLENAME对于每个PSROLEUSER都是唯一的。

SELECT  PSROLEUSER 
FROM    sysadm.PSROLEUSER 
WHERE   ROLENAME IN ('NCC_Manag', 'HRM-Content Amin')
GROUP   BY PSROLEUSER
HAVING  COUNT(*) = 2

• 关系部门的SQL

Answer 2

这是一种将所有逻辑放在having子句中的方法：

select PSROLEUSER
from sysadm.PSROLEUSER 
group by PSROLEUSER
having sum(case when ROLENAME = 'NCC_Manag' then 1 else 0 end) > 0 and
       sum(case when ROLENAME = 'HRM-Content Amin' then 1 else 0 end) > 0;

我喜欢这种方法，因为它很笼统。 举例来说，如果你希望所有'NCC_Manag' 不在 'HRM_Content Amin' ，你会怎么做：

select PSROLEUSER
from sysadm.PSROLEUSER 
group by PSROLEUSER
having sum(case when ROLENAME = 'NCC_Manag' then 1 else 0 end) > 0 and
       sum(case when ROLENAME = 'HRM-Content Amin' then 1 else 0 end) = 0;

Answer 3

其他方式：

select X.PSROLEUSER from
(select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'NCC_Manag') X inner join 
(select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'HRM-Content Amin') Y
on X.PSROLEUSER = Y.PSROLEUSER

Answer 4

select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME in('NCC_Manag','HRM-Content Amin')

试试这个代码

Answer 5

select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'NCC_Manag'
UNION
select PSROLEUSER from sysadm.PSROLEUSER where ROLENAME = 'HRM-Content Amin'

假设它们返回相同的架构，只需对其进行合并。

Answer 6

您也可以将另一个版本与EXISTS运算符一起使用。

SELECT t1.PSROLEUSER
FROM sysadm.PSROLEUSER t1
WHERE t1.ROLENAME = 'NCC_Manag'
  AND EXISTS (
              SELECT 1
              FROM sysadm.PSROLEUSER t2
              WHERE t2.ROLENAME = 'HRM-Content Amin'
                AND t1.PSROLEUSER = t2.PSROLEUSER
              )

参见有关SQLFiddle演示

Answer 7

select distinct psroleuser from psroleuser where rolename = 'NCC_Manag'
and psroleuser in 
(select psroleuser from psroleuser where rolename = 'HRM-Content Amin')