Question

i have a table in database , and i want write query code to select collective date between two record .

this is sample code :

table is :

CREATE TABLE `user` (
  `userid` int(11) NOT NULL AUTO_INCREMENT,
  `startdate` date NOT NULL,
  `enddate` date NOT NULL,
  PRIMARY KEY (`userid`)
) 

example 1
and i have 2 record in table .

(userid =>1 , startdate => ‘2012-02-02’ , enddate => ‘2012-10-02’)
(userid =>2 , startdate => ‘2012-04-02’ , enddate => ‘2012-09-02’)

i want select query to give range ‘2012-04-02’ until ‘2012-09-02’

example 2
and i have 2 record in table .

(userid =>1 , startdate => ‘2012-02-02’ , enddate => ‘2012-02-12’)
(userid =>2 , startdate => ‘2012-04-02’ , enddate => ‘2012-09-02’)

i want select query to give null range

is there best query for this?

Answer 1

If I’ve got it right and you need time period that is an intersection of periods from these rows:

select * from
(
    select max(startdate) d1, min(enddate) d2 from user
) where d1<=d2