Howdy, Marcel,
In the example output you provided the ID = 2 should have just one record...Ain't I right?
Best,
Oliveiros
----- Original Message -----
Sent: Wednesday, June 15, 2011 4:23 PM
Subject: [SQL] Merge overlapping time-periods
Hi!
Although I try for some time, I am not able to write an SQL-Query that can do the following:
I have a very big table (lets call it mytable) with information like this:
ID BEG END
1 2000-01-01 2000-03-31
1 2000-04-01 2000-05-31
1 2000-04-15 2000-07-31
1 2000-09-01 2000-10-31
2 2000-02-01 2000-03-15
2 2000-01-15 2000-03-31
2 2000-04-01 2000-04-15
3 2000-06-01 2000-06-15
3 2000-07-01 2000-07-15
Theres an ID and time periods defined by a start value (BEG) and an end value (END)
I want to merge all periods belonging to the same ID, iff their time periods are overlapping or in a direct sequence.
Therefore the result should somehow look like this:
ID BEG END
1 2000-01-01 2000-07-31
1 2000-09-01 2000-10-31
2 2000-01-15 2000-03-31
2 2000-04-01 2000-04-15
3 2000-06-01 2000-06-15
3 2000-07-01 2000-07-15
I tried using WITH RECURSIVE but I didnt succeed.
My server is PostgreSQL 8.4. Unfortunately I cant do anything like update or install some fancy module
Thank you for your help!
Best regards,
Marcel Jira