小美是一所中學(xué)的信息科技老師，她有一張?seat?座位表，平時(shí)用來(lái)儲(chǔ)存學(xué)生名字和與他們相對(duì)應(yīng)的座位 id。

其中縱列的?id?是連續(xù)遞增的

小美想改變相鄰倆學(xué)生的座位。

你能不能幫她寫(xiě)一個(gè) SQL query?來(lái)輸出小美想要的結(jié)果呢？

示例：

+---------+---------+

| id | student |

+---------+---------+

| 1 | Abbot |

| 2 | Doris |

| 3 | Emerson |

| 4 | Green |

| 5 | Jeames |

+---------+---------+

假如數(shù)據(jù)輸入的是上表，則輸出結(jié)果如下：

+---------+---------+

| id | student |

+---------+---------+

| 1 | Doris |

| 2 | Abbot |

| 3 | Green |

| 4 | Emerson |

| 5 | Jeames |

+---------+---------+

注意：

如果學(xué)生人數(shù)是奇數(shù)，則不需要改變最后一個(gè)同學(xué)的座位。

# Write your MySQL query statement below

SELECT * FROM(

SELECT id-1 AS id,student FROM seat WHERE id%2=0

UNION

SELECT id+1 AS id,student FROM seat WHERE id%2=1 AND (id+1) <= (SELECT COUNT(*) FROM seat)

UNION

SELECT id AS id,student FROM seat WHERE id%2=1 AND (id+1) > (SELECT COUNT(*) FROM seat)

) AS T1

ORDER BY id ASC

標(biāo)簽：數(shù)據(jù)庫(kù),seat,力扣,student,query,座位,id,SELECT

來(lái)源： https://www.cnblogs.com/JAYPARK/p/10351175.html