Question

I am working on a PHP application that displays events. It generates a select box that allows visitors to choose a month for which events should be displayed.

My problem is in regard to the select box, which should display not only months on which an event starts or ends, but also months during which an event is still taking place (even if it started months before and ends months later).

Here is what I’ve got at the moment, it’s pretty basic and only returns months on which events start.

SELECT 
  DISTINCT DATE_FORMAT(start,'%M %Y') as prettydate, 
  DATE_FORMAT(start,'%m%Y') as monthyear 
FROM 
  `events` 
WHERE 
  start >= NOW() 
ORDER BY 
  start ASC;

How can I also get February & July but also March, April, May & June 2014 in the result if the only event I’ve got in 2014 starts in February and finishes in July for example?

Thanks in advance for your help!

Answer 1

Assuming you don’t have any events that span more than 1 year, and using the following start/end dates:

('2012-01-01','2012-01-31'),
('2012-03-01','2012-03-31'),
('2012-05-01','2012-06-01'),
('2012-07-01','2012-07-31'),
('2012-09-01','2012-10-31'),
('2012-11-01','2012-11-30');

this query:

SELECT DISTINCT
  DISTINCT DATE_FORMAT(e.start + INTERVAL ids.id MONTH,'%M %Y') as prettydate, 
  DATE_FORMAT(e.start + INTERVAL ids.id MONTH,'%m%Y') as monthyear 
FROM 
(
  SELECT 0 AS id
  UNION SELECT 1
  UNION SELECT 2
  UNION SELECT 3
  UNION SELECT 4
  UNION SELECT 5
  UNION SELECT 6
  UNION SELECT 7
  UNION SELECT 8
  UNION SELECT 9
  UNION SELECT 10
  UNION SELECT 11
) ids,
  events e
WHERE
  EXTRACT(YEAR_MONTH FROM e.start + INTERVAL ids.id MONTH) <=
  EXTRACT(YEAR_MONTH FROM e.end)
ORDER BY 
  e.start + INTERVAL ids.id MONTH

will return:

prettydate      monthyear
January 2012    012012
March 2012      032012
May 2012        052012
June 2012       062012
July 2012       072012
September 2012  092012
October 2012    102012
November 2012   112012

See http://sqlfiddle.com/#!2/12b08/3 for a working example.