在postgres中生成星期间隔的日期

Question

I want a series in PostgreSQL which gives the date of every week interval before that date

Examples

 1) Date Selected is 05/31/2013 So the series must be : 05/31/2013 05/24/2013 05/17/2013 05/03/2013 04/26/2013 2) Date Selected is 05/20/2013 So the series must be : 05/20/2013 05/13/2013 05/06/2013 04/29/2013 04/22/2013 

What I have done:

SELECT * 
FROM generate_series('2013-05-03 00:00'::timestamp,'2013-05-31 12:00', '1 weeks')

• It gives an increasing series from 2013-05-03.
• I want a decreasing series from 2013-05-31

Answer 1

Is it what you're after?

SELECT *
  FROM generate_series('2013-05-31 12:00'::timestamp,
                       '2013-05-03', '-1 weeks');