修改SQL查詢以獲取所有用戶？

我目前有這個查詢。修改SQL查詢以獲取所有用戶？

SELECT DISTINCT (o.customer_id), count(o.id) AS orders, c.* 
FROM `order` AS o LEFT JOIN customer AS c ON o.customer_id = c.id 
GROUP BY customer_id

它是什麼，它返回已發出的命令，並計算每個訂單的客戶取得了數所有客戶。

我需要做的是修改此查詢，以便它還返回那些還沒有下單的客戶。你有什麼想法如何做到這一點？

我試圖扭轉查詢但這並沒有這樣的伎倆..

SELECT DISTINCT (o.customer_id), count(o.id) AS orders, c.* 
FROM customer AS c LEFT JOIN order AS o ON o.customer_id = c.id 
GROUP BY o.customer_id

來源

2011-04-07 John

你已經寫了'DISTINCT（o.customer_id）'那麼需要什麼 'GROUP BY customer_id' – diEcho 2011-04-07 09:41:47

這個distinct在t中什麼都不做他的情況.. – 2011-04-07 09:43:27

你試過用'RIGHT JOIN'嗎？ – diEcho 2011-04-07 09:51:45

試試這個。

SELECT o.customer_id, sum(case when o.id is not null then 1 else 0 end) AS orders, c.* 
FROM customer c 
LEFT JOIN order o ON o.customer_id = c.id GROUP BY customer_id

來源

2011-04-07 09:37:21

什麼：

SELECT DISTINCT (o.customer_id), count(o.id) AS orders, c.* 
    FROM `order` AS o 
    LEFT OUTER JOIN customer AS c ON o.customer_id = c.id GROUP BY customer_id

來源

2011-04-07 09:39:14 Lazarus

SELECT o.customer_id, c.* 
FROM customer AS c LEFT JOIN order AS o ON o.customer_id = c.id 
WHERE o.id IS NULL 
GROUP BY o.customer_id

您也可以跳過「GROUP BY」子句，因爲當訂貨方是NULL，則永遠爲客戶着想只有一行：

SELECT o.customer_id, c.* 
FROM customer AS c LEFT JOIN order AS o ON o.customer_id = c.id 
WHERE o.id IS NULL

來源

2011-04-07 09:45:27

修改SQL查詢以獲取所有用戶？

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