获取两个日期之间的时差统计

Question

I have 2 tables in MYSQL. The first contain all my bookings with the date the booking was made and the second contain all my tours available dates in datetime format.

This is an example how it looks like: 4 booking made for 2 different tours.

Table: myBooking

ID DATEADD               IDTOUR
1  2020-08-01 13:30:00   1
2  2020-08-02 13:30:00   1
3  2020-08-03 13:30:00   2
4  2020-08-09 13:30:00   2

Table: myTours

ID  TOUR
1   2020-08-10 13:30:00
2   2020-08-11 13:30:00

I would like to have in PHP/MYSQL an overview of the time interval in which the customers book.

I would like to display:

For the bookings made less than 24 hours, the total number of booking that were made less than 1 hour before the date of the tour, between 1 hour and 2 hours etc...

Then, for the booking made more than 24 hours, the number of days between the booking and the date of the tour.

I find out DATEDIFF to get time interval between the 2 dates but i need help in order to complete the query and correctly display the results.

SELECT DATEDIFF(DATEADD, TOUR) as total FROM myBooking JOIN myTours ON myBooking.IDTOUR = myTours.ID

the result should look like:

< 1hour : (number of bookings made less than 1hour before the tour)
1-2hours : (number of bookings made between 1-2hours before the tour)
3-4hours : (number of bookings made between 3-4hours before the tour)

etc untill 24h...

2 days : (number of bookings made 2 days before the tour)
3 days : (number of bookings made 3 days before the tour)

etc until 30 days...

Answer 1

I find out DATEDIFF to get time interval between the 2 dates but i need help in order to complete the query and correctly display the results.

DATEDIFF is not applicable for this task because:

1. For some rows you need the difference in hours - DATEDIFF calculates the difference in days only.
2. DATEDIFF truncates time part before calculatoin.

The solution may be, for example (schematically):

SELECT ...
         CASE WHEN TIMESTAMPDIFF(HOUR, booking.date, tour.date) < 24
              THEN CONCAT(TIMESTAMPDIFF(HOUR, booking.date, tour.date), ' hours')
              ELSE CONCAT(TIMESTAMPDIFF(DAY, booking.date, tour.date), ' days')
              END AS IntervalLength
...
GROUP BY IntervalLength
...

This will give statistic for each separate hour/day.

---

If you need strictly described statistic periods (<1, 1-2, 3-4, ...) then create separate table like:

CREATE TABLE periods ( hours_from INT, hours_till INT, name INT );
INSERT INTO periods VALUES
(0,0,'<1 hour'),
(1,2,'1-2 hours'),
...
(24,47,'1 day'),
...
(720,743,'30 days'),
(744,99999999,'over 30 days');

join it to your table by

ON TIMESTAMPDIFF(HOUR, booking.date, tour.date) 
   BETWEEN periods.hours_from 
       AND periods.hours_till

and group by periods.name .