MySQL查詢，MAX（）+ GROUP BY + WHERE

Question

如何得到每個分組集合包含最大值的行？ 我有這個mysql

SELECT ticketId, version, storeId, `status` FROM ticket where storeId = 1 AND status = 0; 

並得到結果。

而且我想找到不同ticketId最大版本，行會

ticket | version | storeId | status 
--- 
    1 | 5  | 1  | 0 
    2 | 5  | 1  | 0 

了MySQL怎麼會？

Answer 1

使用聚合函數max：

select ticketId, 
    max(version), 
    storeId, 
    `status` 
from ticket t 
where storeId = 1 
    and status = 0 
group by ticketId, 
    storeId, 
    `status` 

如果ONLY_FULL_GROUP_BY被禁用，你可以使用：

select ticketId, 
    max(version), 
    storeId, 
    `status` 
from ticket t 
where storeId = 1 
    and status = 0 
group by ticketId; 

Answer 2

只需使用group by和max：

SELECT ticketId as ticket, MAX(version) AS version, storeId, `status` 
FROM ticket 
WHERE storeId = 1 
AND status = 0 
GROUP BY ticketId