Incremental and decremental count based on a date

Name Start_date end_date
aaa  01/02/2017  05/03/2017
bbb  03/05/2017  07/07/2017
ccc  02/01/2017  10/09/2017
I want to write a query that calculates the number of people who exist in
the DB in a certain month/year.

Answer:

Jan 2017  1
Feb 2017  2
Mar 2017  3
Apr 2017  3
May 2017  2 (one person - aaa ,ended in May 2017)
Jun 2017  2
Jul 2017  1 (bbb ended in July 2017)
How do I write a PSQL query to get the desired output?

Thanks.



--
Sent from: http://www.postgresql-archive.org/PostgreSQL-novice-f2132464.html