# 626. 换座位
# https://leetcode-cn.com/problems/exchange-seats/

# SQL架构
Create table If Not Exists Seat (id int, student varchar(255));
Truncate table Seat;
insert into Seat (id, student) values ('1', 'Abbot');
insert into Seat (id, student) values ('2', 'Doris');
insert into Seat (id, student) values ('3', 'Emerson');
insert into Seat (id, student) values ('4', 'Green');
insert into Seat (id, student) values ('5', 'Jeames');

# Write your MySQL query statement below
select
    s1.id as id,
    coalesce(s2.student, s1.student) as student
from
    Seat s1
    left join Seat s2 on ((s1.id + 1) ^ 1) - 1 = s2.id
order by
    s1.id;

# clean-up
drop table Seat;