Question

好的伙计们，我很遗憾地问这个，因为我看过几个mysql JOIN示例，但我似乎无法让它工作。

“销售”

----------------------
idcustomer | datecode 
----------------------
 1         | 20120503 
 1         | 20120503 
 1         | 20120503 
 2         | 20120503 
 3         | 20120503

我想知道谁是最大的买家....就多年来客户在特定的日子购买东西而言（是的，我使用一些奇怪的格式，我知道的日期，请不要错过）...我也这样做：

SELECT idcustomer, COUNT(idcustomer) FROM sales WHERE datecode = 20120503 GROUP BY idcustomer ORDER BY COUNT(idcustomer) DESC

我得到了：

-----------------------------
idcustomer | Count(idcustomer)
-----------------------------
 1         | 3
 2         | 1
 3         | 1

问题是......因为我也有桌子：

“客户”

----------------------
| name | id_customer |
----------------------
 Jess  | 1
 Matt  | 2
 Perry | 3

以下是我想要实现的......怎么做？

---------------------------------------------
customer.name | idcustomer | Count(idcustomer)
---------------------------------------------
 Jess         | 1          | 3
 Matt         | 2          | 1
 Perry        | 3          | 1

Answer 1

SELECT customer.name, idcustomer, COUNT(idcustomer)
FROM sales
JOIN customer
ON sales.idcustomer = customer.id_customer
WHERE datecode = 20120503
GROUP BY idcustomer
ORDER BY COUNT(idcustomer) DESC

查看在线工作：sqlfiddle

Answer 2

你需要这样做 -

SELECT idcustomer, c.name, COUNT(idcustomer) 
FROM sales s inner join customer c on (s.idcoustomer=c.id_customer)  
WHERE datecode = 20120503 
GROUP BY idcustomer, c.name  
ORDER BY COUNT(idcustomer) DESC

Answer 3

希望这会有所帮助::

Select cust_ref.idcustomer, cust_ref.COUNT(idcustomer), customer.name
from 
(SELECT idcustomer, COUNT(idcustomer) FROM sales WHERE datecode = 20120503 
 GROUP BY idcustomer) cust_ref
 inner join customer on (sales.idcustomer = customer.id_customer)
ORDER BY COUNT(idcustomer) DESC

Answer 4

SELECT 
  t1.name,t2.count_buy,t2.idcustomer 
   FROM customer as t1,
 (SELECT 
    idcustomer,COUNT(idcustomer) as count_buy 
       FROM `sales`  
        WHERE datecode = 20120503
        GROUP BY idcustomer 
         ORDER BY COUNT(idcustomer) DESC) t2
  WHERE 
   t1.idcustomer =t2.idcustomer

mysql + JOIN查询问题

4 个答案: