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標題: Simple SQL question [打印本頁]

作者: luckiejacky 時間: 2013-9-8 11:23 標題: Simple SQL question

select count(c.CustomerID)
from customers AS c INNER JOIN orders AS o
ON (c.CustomerID = o.CustomerID)
where DATE(o.PurchaseDateTime) BETWEEN CURDATE() - INTERVAL 1 MONTH AND CURDATE()
group by c.CustomerID

複製代碼

This results in every CustomerID joining with every order
So if I have 6 customers
The results will be
6
1
1
1
1
1
How can I only get the first number, but I need o.PurchaseDateTime
Because I want to include the range of dates in the query.
Thanks

作者: 杜龍 時間: 2013-9-8 13:05

select ..... order by ? limit 1, 1?

作者: KinChungE 時間: 2013-9-8 15:46

select ..... order by ? limit 1, 1?
杜龍發表於 2013-9-8 13:05

+1, 先order by再limit

(假設你用緊MySQL)

作者: 神秘二代 時間: 2013-9-8 20:53

加個max唔得?
select max(count(c.CustomerID)) ......

作者: franklee006 時間: 2013-9-9 09:58

select ..... order by ? limit 1, 1?
杜龍發表於 2013-9-8 13:05

你1, 1 會選左第一個, 應該係 0, 1