Question

我有这样的查询，这是解决该查询的最佳方法？

SELECT month(createdat), year(createdat), sum(quantity) from (
SELECT 
    sum(omd.quantity), omd.createdat
FROM
    order_match_detail omd, order_match om
WHERE
   omd.order_match_id = om.id
   AND omd.product_id = 144
   and om.order_status_id in (4, 5, 6, 8)
        AND NOT EXISTS( SELECT 
            1
        FROM
            order_match_detail omd1,
            order_match om1
        WHERE
            omd1.order_match_id = om1.id
                AND om1.createdAt < om.createdAt
                AND omd1.product_id = 144
                AND om1.order_status_id in (4, 5, 6, 8))) z
group by month(createdat), year(createdat) order by 2 asc, 1 asc;

它表示我运行此查询Error Code : 1054. Unknown column 'quantity' in 'field list'时这是预期结果（基于小提琴），其中product_id = 144，而order_status_id位于（4，5，6，8）

    +--------+------+---------------+
    | Month  | Year | Sum(Quantity) |
    +--------+------+---------------+
    |      1 | 2019 |            50 |
    |      2 | 2019 |            34 |
    +--------+------+---------------+

样本数据集和相同的小提琴

CREATE TABLE order_match ( id INT(11), 
                                       createdAt datetime, 
                                       order_status_id INT(10)
                               );
INSERT INTO order_match  VALUES
(1,'2019-01-01',4),
(2,'2019-01-10',5),
(3,'2019-01-20',6),
(4,'2019-02-10',7),
(5,'2019-02-15',4),
(6,'2019-02-21',5),
(7,'2019-01-02',6),
(8,'2019-01-11',8),
(9,'2019-01-18',7),
(10,'2019-02-06',5);

CREATE TABLE order_match_detail (id int(11),
                                 order_match_id INT(11), quantity int(11), product_id int(11));
INSERT INTO order_match_detail VALUES 
(1, 1, 20, 144),
(2, 2, 30, 144), 
(3, 3, 24, 100), 
(4, 4, 34, 144), 
(5, 5, 43, 120), 
(6, 6, 34, 144), 
(7, 7, 23, 442), 
(8, 8, 23, 24), 
(9, 9, 24, 12), 
(10,10, 24, 24);

http://sqlfiddle.com/#!9/81e3aa/2

Answer 1

您真的是在做这顿饭...：-（

SELECT DATE_FORMAT(o.createdat,'%Y-%m') yearmonth
     , SUM(quantity) total 
  FROM order_match o 
  JOIN order_match_detail d 
    ON d.order_match_id = o.id 
 WHERE o.order_status_id IN (4,5,6,8)
   AND d.product_id = 144
 GROUP 
    BY yearmonth;
+-----------+-------+
| yearmonth | total |
+-----------+-------+
| 2019-01   |    50 |
| 2019-02   |    34 |
+-----------+-------+

Answer 2

我认为您的问题出在第一个子查询上。您的列不称为“数量”，而是“ sum（omd.quantity）”。您必须为子查询中的列赋予别名，如下所示：

SELECT month(createdat), year(createdat), sum(quantity) from (
SELECT 
    sum(omd.quantity) AS quantity, omd.createdat
FROM ...

dit：这样一来，我就解决了您的提琴：http://sqlfiddle.com/#!9/81e3aa/5/0

但是：尽管它创建了您想要的结果，但并未考虑以下情况：

om1.createdAt < om.createdAt

更改数据会导致其他值，我认为结果应该保持不变：http://sqlfiddle.com/#!9/88c2e1/1/0

你怎么看？

在选择关于子查询的mysql中选择

2 个答案: