Reputation: 7933
Assume this is my table:
ID NUMBER DATE
------------------------
1 45 2018-01-01
2 45 2018-01-02
2 45 2018-01-27
I need to separate using partition by and row_number where the difference between one date and another is greater than 5 days. Something like this would be the result of the above example:
ROWNUMBER ID NUMBER DATE
-----------------------------
1 1 45 2018-01-01
2 2 45 2018-01-02
1 3 45 2018-01-27
My actual query is something like this:
SELECT ROW_NUMBER() OVER(PARTITION BY NUMBER ODER BY ID DESC) AS ROWNUMBER, ...
But as you can notice, it doesn't work for the dates. How can I achieve that?
Upvotes: 11
Views: 37660
Reputation: 31991
by using lag
and datediff
funtion
select * from
(
select t.*,
datediff(day,
lag(DATE) over (partition by NUMBER order by id),
DATE
) as diff
from t
) as TT where diff>5
http://sqlfiddle.com/#!18/130ae/11
Upvotes: 2
Reputation: 1270773
I think you want to identify the groups, using lag()
and datediff()
and a cumulative sum. Then use row_number()
:
select t.*,
row_number() over (partition by number, grp order by date) as rownumber
from (select t.*,
sum(grp_start) over (partition by number order by date) as grp
from (select t.*,
(case when lag(date) over (partition by number order by date) < dateadd(day, 5, date)
then 1 else 0
end) as grp_start
from t
) t
) t;
Upvotes: 1
Reputation: 50173
You can use lag
function :
select *, row_number() over (partition by number, grp order by id) as [ROWNUMBER]
from (select *, (case when datediff(day, lag(date,1,date) over (partition by number order by id), date) <= 1
then 1 else 2
end) as grp
from table
) t;
Upvotes: 6