Several friends at a cinema ticket office would like to reserve consecutive available seats.
Can you help to query all the consecutive available seats order by the seat_id using the following cinema
table?
| seat_id | free |
|---------|------|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
Your query should return the following result for the sample case above.
| seat_id |
|---------|
| 3 |
| 4 |
| 5 |
Note:
- The seat_id is an auto increment int, and free is bool ('1' means free, and '0' means occupied.).
- Consecutive available seats are more than 2(inclusive) seats consecutively available.
这个题目参考solution, 就是先得到seat_id 和所有seat_id对应的表格, 然后再选两个的差值是1的, 最后Distinct 并且 in order.
Code
SELECT DISTINCT c1.seat_id FROM cinema AS c1 JOIN cinema AS c2 WHERE abs(c1.seat_id - c2.seat_id) = 1 and c1.free = True and c2.free = True
order by c1.seat_id