Join results of multiple select statements in sql - sql

Question

I have four select statements and I want to join them all to only get the common rows.
In an example, I'm providing 2 select statements:
SELECT
h.userid, 'Activity' as table_name,
h.stamp,
DATEDIFF(dd, kh.LatestDate, GETDATE()) as days_since,
m.group_name
FROM
([Animal].[SYSADM].[activity_history] h
INNER JOIN
(SELECT userid, MAX(stamp) as LatestDate
FROM [Animal].[SYSADM].[activity_history]
GROUP BY userid) kh ON h.userid = kh.userid AND h.stamp = kh.LatestDate)
LEFT OUTER JOIN
[Animal].[SYSADM].secure_member m ON m.user_name = h.userid
WHERE
(DATEDIFF(dd, kh.LatestDate, GETDATE()) > 90)
AND NOT (m.group_name = 'inactive')
ORDER BY
userid
SELECT
h.userid, 'Person' as table_name, h.stamp,
DATEDIFF(dd, kh.LatestDate, GETDATE()) as days_since,
m.group_name
FROM
([Animal].[SYSADM].[person_history] h
INNER JOIN
(SELECT userid, max(stamp) as LatestDate
FROM [Animal].[SYSADM].[person_history]
GROUP BY userid) kh ON h.userid = kh.userid AND h.stamp = kh.LatestDate)
LEFT OUTER JOIN
[Animal].[SYSADM].secure_member m ON m.user_name = h.userid
WHERE
(DATEDIFF(dd, kh.LatestDate, GETDATE()) > 90)
AND NOT (m.group_name = 'inactive')
ORDER BY
userid
I have tried INTERSECT, but it's not returning any rows, I want to see the common rows from both the select statements (actually I have 4 so I believe what works for 2 will work for 4)
Thanks in advance.
Update:
I tried inner join on 2 select statements and it gave me the desired result but now the question is how I can use inner join on 4 select statements.
SELECT DISTINCT t1.userid as A_UserID, t2.userid as P_UserID, t1.stamp as A_stamp, t2.stamp as P_stamp, datediff(dd,t1.stamp,GetDate()) as A_days_since, datediff(dd,t2.stamp,GetDate()) as P_days_since, t1.group_name, t1.table_name, t2.table_name
from
(SELECT h.userid, 'Activity' as table_name, h.stamp, datediff(dd,kh.LatestDate,GetDate()) as days_since, m.group_name
FROM
( [Animal].[SYSADM].[activity_history] h
inner join (
select userid, max(stamp) as LatestDate
from [Animal].[SYSADM].[activity_history]
group by userid
) kh on h.userid = kh.userid and h.stamp = kh.LatestDate
)
left outer join [Animal].[SYSADM].secure_member m on m.user_name = h.userid
where
(datediff(dd,kh.LatestDate, GetDate()) > 90)
and not (m.group_name = 'inactive')) t1
inner join
(SELECT h.userid, 'Person' as table_name, h.stamp, datediff(dd,kh.LatestDate,GetDate()) as days_since, m.group_name
FROM
( [Animal].[SYSADM].[person_history] h
inner join (
select userid, max(stamp) as LatestDate
from [Animal].[SYSADM].[person_history]
group by userid
) kh on h.userid = kh.userid and h.stamp = kh.LatestDate
)
left outer join [Animal].[SYSADM].secure_member m on m.user_name = h.userid
where
(datediff(dd,kh.LatestDate, GetDate()) > 90)
and not (m.group_name = 'inactive')) t2
on
t1.userid = t2.userid
order by T1.userid
Query Result

Answer 1

Forget about the UNION for a moment. Imagine you take that result and insert into Table1
Then depend what you mean the "common rows". If you want exact value but in different tables
SELECT userid, h.stamp, days_since, m.group_name
FROM Table1
GROUP BY userid, h.stamp, days_since, m.group_name
HAVING COUNT( table_name ) = 2 -- in this case 2 because are two types
-- Activity and Persons
After viewing your query result you also need to add DISTINCT to each of the queries on the UNION.