Continous date availability query in MySQL? - php

Question

I have a table in my db, which contains following data:
————————————————————————————————————————————————————————————————————————
Id startDate availabilityStatus Hotel_Id
————————————————————————————————————————————————————————————————————————
1 2016-07-01 available 2
2 2016-07-02 available 2
3 2016-07-03 unavailable 2
4 2016-07-04 available 3
5 2016-07-05 available 3
6 2016-07-06 available 3
7 2016-07-07 unavailable 4
8 2016-07-08 available 4
9 2016-07-09 available 4
10 2016-07-10 available 4
Now, user wants to see all the Hotels which have 3 continuous days availability in July’16.
I am able to make the query to get the availability, but not sure how to fetch the Continuous date availability.
As per the above data, in July only Hotel Id 3, 4 have the continuous available dates, but as 2 also have the dates available. so how should we remove 2 and show just 3, 4 via MySQL query.
Please advise?

Answer 1

You can use the following query:
SELECT DISTINCT t1.hotel_id
FROM mytable AS t1
JOIN mytable AS t2
ON t1.hotel_id = t2.hotel_id AND
DATEDIFF(t1.startDate, t2.startDate) = 2 AND
t1.availabilityStatus = 'available' AND
t2.availabilityStatus = 'available'
LEFT JOIN mytable AS t3
ON t1.hotel_id = t3.hotel_id AND
t3.startDate < t2.startDate AND t3.startDate > t1.startDate AND
t3.availabilityStatus = 'unavailable'
WHERE t3.hotel_id IS NULL
The query is written in such a way, so that it can easily be adjusted in order to accommodate longer availability periods.
Edit:
Here's a solution using variables:
SELECT DISTINCT hotel_id
FROM (
SELECT hotel_id,
#seq := IF(#hid = hotel_id,
IF(availabilityStatus = 'available', #seq + 1, 0),
IF(#hid := hotel_id,
IF(availabilityStatus = 'available', 1, 0),
IF(availabilityStatus = 'available', 1, 0))) AS seq
FROM mytable
CROSS JOIN (SELECT #seq := 0, #hid := 0) AS vars
ORDER BY hotel_id, startDate) AS t
WHERE t.seq >= 3
You can test it with your actual data set and tell us how it compares with the first solution.

Answer 2

Try something like that. It works for any number of days. Replace N with 3.
SELECT DISTINCT A.Hotel_Id FROM table A
WHERE
A.availabilityStatus = 'available' AND
N-1 = (
SELECT count(DISTINCT startDate) FROM table B
WHERE B.availabilityStatus = 'available'
AND A.Hotel_Id = B.Hotel_Id
AND B.startDate
BETWEEN DATE_ADD(A.startDate, INTERVAL 1 DAY)
AND DATE_ADD(A.startDate, INTERVAL N-1 DAY)
)
It works like that: for each available date, count available dates in N-1 next days. If their count is N-1, add hotel_id to results.

Answer 3

Try this. I didn't get chance to test it as sqlfiddle is not working, but the general idea is to take 2 more instance of table by adding 1 and 2 days to the start date respectively.
Then join them based on derived dates and hotel id.
select t1.hotelid from
(select * from Table1 where availabilityStatus='available' ) t1
inner join
(select a.*, DATE_ADD(startDate,INTERVAL 1 DAY) as date_plus_one
from Table1 where availabilityStatus='available' ) t2
on t1.start_date=t2.date_plus_one and t1.hotelid=t2.hotelid
inner join
(select a.*, DATE_ADD(startDate,INTERVAL 2 DAY) as date_plus_two
from Table1 where availabilityStatus='available' ) t3
on t1.start_date=t3.date_plus_two and t1.hotelid=t3.hotelid

Answer 4

This query uses double self-join to find the same hotel available at day a, b and c, split by a day (function ADDDATE).
SELECT DISTINCT a.Hotel_Id
FROM table a
INNER JOIN table b ON a.Hotel_Id=b.Hotel_Id
INNER JOIN table c ON a.Hotel_Id=c.Hotel_Id
WHERE ADDDATE(a.startDate , INTERVAL 1 DAY) = b.startDate
AND ADDDATE(a.startDate , INTERVAL 2 DAY) = c.startDate
AND a.availabilityStatus = 'available'
AND b.availabilityStatus = 'available'
AND c.availabilityStatus = 'available'

Answer 5

Its working fine...
SELECT a.hotel_id FROM `mytable` as a WHERE
(select COUNT(id) from mytable as a1 where
DATE(a1.startDate)=DATE_ADD(a.startDate,INTERVAL 1 DAY) and
a1.hotel_id=a.hotel_id and
a1.availabilityStatus="Available"
) >0
and
(select COUNT(id) from mytable as a1 where
DATE(a1.startDate)=DATE_ADD(a.startDate,INTERVAL -1 DAY) and
a1.hotel_id=a.hotel_id and
a1.availabilityStatus="Available"
) >0
and
(select COUNT(id) from mytable as a1 where
DATE(a1.startDate)=DATE(a1.startDate) and
a1.hotel_id=a.hotel_id and
a1.availabilityStatus="Available"
) >0