Reputation: 69
So say I have this table:
Name | Role |
---|---|
First | Science |
First | Math |
First | Science |
First | Math |
Second | Science |
Third | Math |
Third | Math |
I want to display a column of duplicates for Name/Role ONLY if role is different in each group. So the final result should be like this:
Name | Role |
---|---|
First | Science |
First | Math |
This is the only person that has a different role for the same name (no matter how many times that specific combination is duplicated). That's why even though Third/Math is also duplicated, it doesn't matter because it's the same combination.
I tried doing a CTE as follows:
;with cte as (
Select Name, Role, ROW_NUMBER() over (partition by name order by name) as 'rownum1'
from U.Users
group by u.name, u.role)
so then select * from cte where rownum > 1 gets me my names of people that have this issue but it doesn't display the duplicate roles for that user. Not sure how I should approach it differently?
If I join the CTE table to the original Users table, I also get the single entries.
Upvotes: 1
Views: 52
Reputation: 69
So after I posted question I tried this which isn't as elegant as Kurt's answer but did also work:
;with cte as (select name, role, row_number() over (partition by name order by name) rownum
from user_role
group by name, role)
select distinct user_role.name, user_role.role from user_role
join cte on cte.name=user_role.name and cte.role=user_role.role
where user_role.name in (select name from cte where rownum =2)
https://www.db-fiddle.com/f/vzRDgBXwYp3VpgNyfn9qzL/2
Upvotes: 0
Reputation: 1748
You can take advantage of the fact that window functions are applied after aggregation:
select name, role
from (
select name, role, count(1) over (partition by name) c
from user_role
group by name, role
) r
where c > 1
https://www.db-fiddle.com/f/vzRDgBXwYp3VpgNyfn9qzL/0
Upvotes: 2
Reputation: 384
You can try something like this:
WITH cte1 as (
SELECT distinct *
FROM
table1
),
cte2 as
(
Select Name, Role, ROW_NUMBER() over (partition by name order by name) as rnk
from cte1 u
group by u.name, u.role
)
SELECT * FROM cte2
where name in
(select name
from cte2
WHERE rnk > 1
group by name
)
I used a distinct function to remove any duplicates, then use the ROW_NUMBER() like you to find Names with multiple rows.
Upvotes: 0