refactor 626

Author: fishercoder1534

database/_626.sql

@@ -1,33 +1,3 @@
---626. Exchange Seats
---
---Mary is a teacher in a middle school and she has a table seat storing students' names and their corresponding seat ids.
---
---The column id is continuous increment.
---Mary wants to change seats for the adjacent students.
---Can you write a SQL query to output the result for Mary?
---+---------+---------+
---|    id   | student |
---+---------+---------+
---|    1    | Abbot   |
---|    2    | Doris   |
---|    3    | Emerson |
---|    4    | Green   |
---|    5    | Jeames  |
---+---------+---------+
---For the sample input, the output is:
---+---------+---------+
---|    id   | student |
---+---------+---------+
---|    1    | Doris   |
---|    2    | Abbot   |
---|    3    | Green   |
---|    4    | Emerson |
---|    5    | Jeames  |
---+---------+---------+
---Note:
---If the number of students is odd, there is no need to change the last one's seat.
-
-
 SELECT
     (CASE
         WHEN MOD(id, 2) != 0 AND counts != id THEN id + 1