MySQL查詢以及其他表

Question

算我想從一個表中獲取數據，並計算從其他表中的所有結果，根據第一表數據，這裏是我的嘗試：

SELECT 
    cars.*, (
     SELECT 
      COUNT(*) 
     FROM 
      uploads 
     WHERE 
      uploads.cid = cars.customer 
    ) AS `count`, 
FROM 
    `cars` 
WHERE 
    customer = 11; 

我不真的有一個想法，爲什麼它不工作，因爲我不是一個普通的MySQL用戶/編碼器...

任何人都可以指引我在這個正確的方向嗎？

Answer 1

SELECT 
    c.*, COUNT(u.cid) AS count 
FROM 
    cars c 
LEFT JOIN 
    uploads u 
ON 
    u.cid=c.customer 
WHERE 
    u.customer = 11; 
GROUP BY c.cid 

Answer 2

使用LEFT JOIN

SELECT a.customer, COUNT(b.cid) totalCount 
FROM cars a 
     LEFT JOIN uploads b 
      ON a.customer = b.cid 
WHERE a.customer = 11 
GROUP BY a.customer 

在LEFT JOIN使用COUNT(*)都會有記錄加入這兩個表試試它有1

Answer 3

SELECT cars.*,COUNT(uploads.*) as uplloaded 
from cars 
left outer join uploads on uploads.cid = cars.customer 
where cars.customer = 11 
group by uploads.cid; 

Answer 4

最小計數試試這個：

SELECT customer, COUNT(cid) totalCount 
FROM cars 
     INNER JOIN uploads 
      ON (customer = cid) 
WHERE customer = 11 
GROUP BY customer