錯誤使用ORDER BY和GROUP BY一起

Question

我有一個查詢，低於：

SELECT 
    o.ordernum, 
    o.SCHEDATTEMPT, 
    o.lastcontactdate, 
    MAX(OE.NextContactDate) AS NextContactDate 
FROM orderevents OE 
FULL outer join orde_ o 
ON o.ORDERID=oe.OrderId 
WHERE O.lastcontactdate is not null and SCHEDULED is null and DROPTIME is null  
ORDER by O.LASTcontactdate 

當我執行此查詢我得到的錯誤Column 'orde_.ORDERNUM' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.。

我在這個查詢中做錯了什麼？

Answer 1

錯誤消息說明了一切，但如果您看到它，則其含義更易於理解。

在選擇列表中使用聚合函數（即MAX(OE.NextContactDate)），聚合函數需要包含在你的選擇列表中的所有條目...您的選擇列表

SELECT 
    MAX(o.ordernum),  -- technically contained in an aggregate function - setting aside that it's probably not what you want otherwise 
    MAX(o.SCHEDATTEMPT), -- same 
    MAX(o.lastcontactdate), -- same 
    MAX(OE.NextContactDate) AS NextContactDate 
FROM orderevents OE 
FULL outer join orde_ o 
ON o.ORDERID=oe.OrderId 
WHERE O.lastcontactdate is not null and SCHEDULED is null and DROPTIME is null 
ORDER by MAX(o.lastcontactdate) 

... 或條目不被聚合函數包含需要在一個GROUP BY條款：

SELECT 
    o.ordernum, 
    o.SCHEDATTEMPT, 
    o.lastcontactdate, 
    MAX(OE.NextContactDate) AS NextContactDate 
FROM orderevents OE 
FULL outer join orde_ o 
ON o.ORDERID=oe.OrderId 
WHERE O.lastcontactdate is not null and SCHEDULED is null and DROPTIME is null 
GROUP BY o.ordernum, o.SCHEDATTEMPT, o.lastcontactdate -- added GROUP BY clause 
ORDER by o.lastcontactdate 

我懷疑你真正想要的第二修復 - 爲GROUP BY條款添加到您的查詢。