Question

我有两个表订单和order_items

订单表

+----+-----------------------+
| id | total_shipping_charge |
+----+-----------------------+
|  1 | 60                    |
|  2 | 60                    |
|  3 | 60                    |
|  4 | 60                    |
|  5 | 60                    |
|  6 | 0                     |
|  7 | 60                    |
|  8 | 0                     |
|  9 | 60                    |
| 10 | 60                    |
+----+-----------------------+

order_items表

+----+--------------------------+-----+-------+-
| id | order_id | p_name        | qty | price |
+----+----------+---------------+-----+-------+---------------------------------
|  1 |        1 | Product 1     |  1  | 699   |
|  2 |        2 | Product 2     |  1  | 349   |
|  3 |        3 | Product 3     |  1  | 199   |
|  4 |        4 | Product x     |  2  | 299   |
|  5 |        4 | Product y     |  2  | 299   |
|  6 |        4 | Product z     |  2  | 299   |
|  7 |        5 | Product 7     |  2  | 299   |
|  8 |        6 | Product 8     |  1  | 1299  |
|  9 |        7 | Product 9     |  1  | 199   |
| 10 |        8 | Product 10    |  6  | 349   |
+----+----------+---------------------------------------------------------------

现在order_id 4在一个订单中有多个产品，当我加入两个表时，我得到重复的运费。我只想在第一次生吃时运费。

我运行了这个查询

SELECT
    o1.id,
    o1.total_shipping_charge,
    o2.order_id,
    o2.p_name
FROM
    orders o1
INNER JOIN order_items o2 ON o1.id = o2.order_id

但是它显示了运费的重复行，它应该只显示第一行。


| id | total_shipping_charge | order_id | p_name
+----+-----------------------+----------+---------+
|  1 | 60                    |        1 | Product 1  
|  2 | 60                    |        2 | Product 2
|  3 | 60                    |        3 | Product 3
|  4 | 60                    |        4 | Product x
|  5 | 60                    |        4 | Product y
|  6 | 60                    |        4 | Product z 
|  7 | 0                     |        6 | Product 7
|  8 | 60                    |        7 | Product 8
|  9 | 0                     |        8 | Product 9

Answer 1

从Sql Server的角度来看，您要求的是不可能的。您从报告的角度询问哪些是不同的。您可以提取此数据，并在报告中以您希望的方式显示它，但您无法以这种方式提取数据。

不确定MySql的行为。

Answer 2

尝试

SELECT o1.id,o1.total_shipping_charge, distinct o2.order_id,o2.p_name FROM orders o1 INNER JOIN order_items o2 ON o1.id=o2.order_id

sql order和order_items表但只显示一次运费

2 个答案: