Select MAX date using data from several columns SQL - sql

Question

I know this is a much asked question and I've had a look through whats already available but I believe my case is slightly unique (and if it's not please point me in the right direction).
I am trying to find the latest occurrence of a row associated to a user a currently across two tables and several columns.
table: statusUpdate
+-------+-----------+-----------+-------------------+
| id | name | status | date_change |
+-------+-----------+-----------+-------------------+
| 1 | Matt | 0 | 01-01-2001 |
| 2 | Jeff | 1 | 01-01-2001 |
| 3 | Jeff | 2 | 01-01-2002 |
| 4 | Bill | 2 | 01-01-2001 |
| 5 | Bill | 3 | 01-01-2004 |
+-------+-----------+-----------+-------------------+
table: relationship
+-------+-----------+--------------+
| id | userID |stautsUpdateID|
+-------+-----------+--------------+
| 1 | 22 | 1 |
| 2 | 33 | 2 |
| 3 | 33 | 3 |
| 4 | 44 | 4 |
| 5 | 44 | 5 |
+-------+-----------+--------------+
There is a third table which links userID to its own table but these sample tables should be good enough to get my question over.
I am looking to get the latest status change by date. The problem currently is that it returns all instances of a status change.
Current results:
+-------+---------+-----------+-------------------+
|userID |statusID | status | date_change |
+-------+---------+-----------+-------------------+
| 33 | 2 | 1 | 01-01-2001 |
| 33 | 3 | 2 | 01-01-2002 |
| 44 | 4 | 2 | 01-01-2001 |
| 44 | 5 | 3 | 01-01-2004 |
+-------+---------+-----------+-------------------+
Expected results:
+-------+-----------+-----------+-------------------+
|userID |statusID | status | date_change |
+-------+-----------+-----------+-------------------+
| 33 | 3 | 2 | 01-01-2002 |
| 44 | 5 | 3 | 01-01-2004 |
+-------+-----------+-----------+-------------------+
I hope this all makes sense, please ask for more information otherwise.
Just to reiterate I just want to return the latest instance of a users status change by date.
Sample code of one of my attempts:
select
st.ID, st.status, st.date_change, r.userID
from statusUpdate st
inner join Relationship r on st.ID = r.statusUpdateID
inner join (select ID, max(date_change) as recent from statusUpdate
group by ID) as y on r.stausUpdateID = y.ID and st.date_change =
y.recent
Hope someone can point me in the right direction.

Answer 1

use row_number() to get the last row by user
select *
from
(
select st.ID, st.status, st.date_change, r.userID,
rn = row_number() over (partition by r.userID order by st.date_change desc)
from statusUpdate st
inner join Relationship r on st.ID = r.statusUpdateID
) as d
where rn = 1

Answer 2

I ADDED MAX condition to your answer
CREATE TABLE #Table1
([id] int, [name] varchar(4), [status] int, [date_change] datetime)
;
INSERT INTO #Table1
([id], [name], [status], [date_change])
VALUES
(1, 'Matt', 0, '2001-01-01 00:00:00'),
(2, 'Jeff', 1, '2001-01-01 00:00:00'),
(3, 'Jeff', 2, '2002-01-01 00:00:00'),
(4, 'Bill', 2, '2001-01-01 00:00:00'),
(5, 'Bill', 3, '2004-01-01 00:00:00')
;
CREATE TABLE #Table2
([id] int, [userID] int, [stautsUpdateID] int)
;
INSERT INTO #Table2
([id], [userID], [stautsUpdateID])
VALUES
(1, 22, 1),
(2, 33, 2),
(3, 33, 3),
(4, 44, 4),
(5, 44, 5)
select
max(st.ID) id , max(st.status) status , max(st.date_change) date_change, r.userID
from #Table1 st
inner join #Table2 r on st.ID = r.stautsUpdateID
inner join (select ID, max(date_change) as recent from #Table1
group by ID) as y on r.stautsUpdateID = y.ID and st.date_change =
y.recent
group by r.userID
output
id status date_change userID
1 0 2001-01-01 00:00:00.000 22
3 2 2002-01-01 00:00:00.000 33
5 3 2004-01-01 00:00:00.000 44