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CREATE TABLE TEST (StartDate date, EndDate date);
INSERT INTO TEST
SELECT '8/20/2017', '8/21/2017' UNION ALL
SELECT '8/22/2017', '9/22/2017' UNION ALL
SELECT '8/23/2017', '9/23/2017' UNION ALL
SELECT '8/24/2017', '8/26/2017' UNION ALL
SELECT '8/28/2017', '9/19/2017' UNION ALL
SELECT '9/23/2017', '9/27/2017' UNION ALL
SELECT '9/25/2017', '10/10/2017' UNION ALL
SELECT '10/17/2017','10/18/2017' UNION ALL
SELECT '10/25/2017','11/3/2017' UNION ALL
SELECT '11/3/2017', '11/15/2017';
10 rows affected
select *
from test
| StartDate | EndDate |
|---|---|
| 2017-08-20 | 2017-08-21 |
| 2017-08-22 | 2017-09-22 |
| 2017-08-23 | 2017-09-23 |
| 2017-08-24 | 2017-08-26 |
| 2017-08-28 | 2017-09-19 |
| 2017-09-23 | 2017-09-27 |
| 2017-09-25 | 2017-10-10 |
| 2017-10-17 | 2017-10-18 |
| 2017-10-25 | 2017-11-03 |
| 2017-11-03 | 2017-11-15 |
select min(startdate), max(enddate)
from (select t.*,
sum(case when prev_enddate >= startdate then 0 else 1 end) over (order by startdate) as grp
from (select t.*,
max(enddate) over (order by startdate rows between unbounded preceding and 1 preceding) as prev_enddate
from test t
) t
) t
group by grp
order by min(startdate)
| (No column name) | (No column name) |
|---|---|
| 2017-08-20 | 2017-08-21 |
| 2017-08-22 | 2017-10-10 |
| 2017-10-17 | 2017-10-18 |
| 2017-10-25 | 2017-11-15 |