MySQL查询＆＃34; self-tabled＆＃34;行

Question

我有一些桌子

CREATE TABLE receptions (
    id int(11) AUTO_INCREMENT,
    personID int(11),
    manager varchar(255),
    timestamp datetime DEFAULT CURRENT_TIMESTAMP,
    flag tinyint(1),
);

示例：我有一些数据

想要获得行WHERE flag = 1，如

id | personID | "last_manager" | "last_timestamp" | "prev_manager" | "prev_timestamp"

3 | 1 | manager2 | 01.11.2017 11:00:23 | manager1 | 01.11.2017 10:00:00

6 | 2 | manager3 | 01.11.2017 14:00:00 | manager3 | 01.11.2017 13:00:23

......等等。抱歉格式化。

是否可以使用单一查询来获取这种格式的数据？

Answer 1

注意：我还没有尝试过 - 请提供示例数据和预期结果，最好是作为SQLFiddle。但本质上是一个自我连接，MAX可以找到最新的和最新的一行。

    select last.id, 
last.personID,
last.manager as last_manager,
max(last.timestamp) as "last_timestamp",
previous.manager as "prev_manager",
max(previous.timestamp) as "prev_timestamp"
from   receptions last
inner join receptions previous on previous.personid = last.personid
where last.timestamp > previous.timestamp
and last.flag = 1
group by last.id, 
last.personID

Here'是一个SQLFiddle。