如何在SQL

Question

我正在尝试使用两个列（Item, Customer）获取类似数据，根据以下查询，我没有获得重复数据的第一个值。

请帮助我获得如下所示的预期结果。

示例数据

+------+------------+-----------+----------+
| E_ID |   E_Date   |   Item    | Customer |
+------+------------+-----------+----------+
|    1 | 10/10/2017 | Microsoft | DIB      |
|    2 | 10/11/2017 | Oracle    | UNB      |
|    3 | 10/12/2017 | IBM       | UNB      |
|    4 | 10/13/2017 | Microsoft | DIB      |
|    5 | 10/14/2017 | Oracle    | UNB      |
|    6 | 10/15/2017 | SAP       | DIB      |
|    7 | 10/15/2017 | Microsoft | DIB      |
+------+------------+-----------+----------+

我的剧本

SELECT * FROM
(
    SELECT E_ID, E_Date,Item,Customer,
         Row_Number() OVER(PARTITION BY  Customer,Item ORDER By E_ID)AS Rank 
         FROM Events        
) AS B WHERE Rank > 1

预计结果为

+------+------------+----------+----------+
| E_ID |   E_Date   |   Item   | Customer |
+------+------------+----------+----------+
|    1 | 10/10/2017 | Mirosoft | DIB      |
|    4 | 10/13/2017 | Mirosoft | DIB      |
|    7 | 10/15/2017 | Mirosoft | DIB      |
|    2 | 10/11/2017 | Oracle   | UNB      |
|    5 | 10/14/2017 | Oracle   | UNB      |
+------+------------+----------+----------+

我的实际结果

+------+------------+-----------+----------+------+
| E_ID |   E_Date   |   Item    | Customer | Rank |
+------+------------+-----------+----------+------+
|    4 | 10/13/2017 | Microsoft | DIB      |    2 |
|    7 | 10/15/2017 | Microsoft | DIB      |    3 |
|    5 | 10/14/2017 | Oracle    | UNB      |    2 |
+------+------------+-----------+----------+------+

Answer 1

如果我读得正确，您应该使用COUNT代替ROW_NUMBER：

SELECT * FROM
(
    SELECT E_ID, E_Date, Item, Customer,
        COUNT(*) OVER (PARTITION BY Customer, Item) AS cnt
    FROM Events        
) t
WHERE cnt > 1
ORDER BY Item, Customer;

上述查询将返回该组中具有多个记录的每个客户/项目组的记录。

Demo

Answer 2

有很多方法可以做到这一点，一种方法是使用下面的EXISTS子句

SELECT 
  E.E_ID, E.E_Date,E.Item,E.Customer
FROM Events E WHERE EXISTS
( 
    SELECT 1 
    FROM Events E1 
    WHERE 
      E1.E_ID<>E.E_ID 
      AND E.Item=E1.Item 
      AND E.Customer=E1.Customer
)

Answer 3

修改了一下你的查询

join