Question

我正在尝试写一些东西来自动清理一些旅行数据。将这些视为航班：

航班：

ID      DocType     Name        Travel Date     Fare Paid
1       INV     Mrs G       13/03/2017      37.6
2       INV     Mrs G       13/03/2017      200
3       INV     Mr H        14/03/2017      60
4       INV     Mr H        15/03/2017      126
5       CRN     Mr H        15/03/2017      126
6       INV     Mr H        20/03/2017      126
7       INV     Mrs S       29/03/2017      110
8       INV     Mr J        26/03/2017      54
9       INV     Mr R        13/03/2017      200
10      INV     Miss C      27/03/2017      78.98

有时人们会购买航班，然后获得退款。这显示为数据中的两个相同条目，但退款是DocType＆＃39; CRN＆＃39;。我需要能够从数据集中提取预订和退款行。

我可以为CRN标记的行执行此操作。但是，如何拉出CRN行上方的行？相关INV行的ID将始终具有直接且顺序地低于CRN行的ID。

我已经管理了

INSERT INTO TRAVEL.REFUNDS (ID, DocType, Name, [Travel Date], [Fare Paid])
SELECT ID, DocType, Name, [Travel Date], [Fare Paid]
FROM TRAVEL.FLIGHTS
WHERE [DocType] = 'CRN';
GO

提前谢谢

Answer 1

这是SELECT目的，不确定您是想要它还是INSERT或DELETE，但希望它很容易对那些人加以改变，再加上它们修改前要好好检查一下，对吧？

我正在做的是，我使用LAG / LEAD添加一个新列，这主要是其他一些~~行列，虽然向上或向下移动了一行。有了这个，您将每行包含决定如何处理它的所有内容，这将在针对较低查询结果的较高查询中完成。~~

-- Making an MCVE, first time I know its name though. DECLARE @Flights TABLE (ID int, DocType char(3)) INSERT INTO @Flights VALUES ( 1, 'INV') , ( 2, 'INV') , ( 3, 'INV') -- Should not show up. , ( 4, 'CRN') -- Should not show up. , ( 5, 'INV') , ( 6, 'INV') , ( 7, 'INV') , ( 8, 'INV') , ( 9, 'INV') , (10, 'INV') -- Should not show up. , (11, 'CRN') -- Should not show up. -- Querying via LEAD(), with 1 level nesting (or subquerying, I dunno which is which). SELECT * FROM ( SELECT ID , DocType AS DocTypeThis , LEAD(DocType) OVER(ORDER BY ID ASC) AS DocTypeOther -- Seems like the choice of ASC/DESC reverses LAG/LEAD behaviours into each other, although not sure. FROM @Flights ) AS T WHERE (DocTypeOther IS NULL AND DocTypeThis = 'INV') -- Special treatment for last row (for other implementations, might be first row). OR DocTypeThis = DocTypeOther -- This is the core of filtering, this fails only when the row is a 'CRN', or is superceded directly by a 'CRN'. ORDER BY ID ASC

Answer 2

使用exists()：

select *
from t 
where DocType = 'CRN' 
   or exists (
    select 1
    from t i
    where i.DocType='CRN'
      and i.id-1 = t.id
)

或left join

select t.*
from t
  left join t i
    on i.id-1 = t.id 
where t.DocType = 'CRN' 
   or i.DocType = 'CRN'

rextester演示：rextester.com/MSGGX10058

返回：

+----+---------+--------+------------+----------+
| ID | DocType |  Name  | TravelDate | FarePaid |
+----+---------+--------+------------+----------+
|  4 | INV     | Mr H   | 15.03.2017 | 126.00   |
|  5 | CRN     | Mr H   | 15.03.2017 | 126.00   |
+----+---------+--------+------------+----------+

使用not exists()作为相反的结果集：

select *
from t
where DocType = 'INV'
  and not exists (
    select 1
    from t i
    where i.DocType='CRN'
      and i.id-1 = t.id
)

返回：

+----+---------+--------+------------+----------+
| ID | DocType |  Name  | TravelDate | FarePaid |
+----+---------+--------+------------+----------+
|  1 | INV     | Mrs G  | 13.03.2017 | 37.60    |
|  2 | INV     | Mrs G  | 13.03.2017 | 200.00   |
|  3 | INV     | Mr H   | 14.03.2017 | 60.00    |
|  6 | INV     | Mr H   | 20.03.2017 | 126.00   |
|  7 | INV     | Mrs S  | 29.03.2017 | 110.00   |
|  8 | INV     | Mr J   | 26.03.2017 | 54.00    |
|  9 | INV     | Mr R   | 13.03.2017 | 200.00   |
| 10 | INV     | Miss C | 27.03.2017 | 78.98    |
+----+---------+--------+------------+----------+

SQL如何在行的正上方选择行的内容，并将它们移动到新表

2 个答案: