仅选择第一个反向重复

如何解决仅选择第一个反向重复

我在SQL Server 2014数据库中具有下表：

+----+-------+--------+---------+
| ID | CODE  | NUMBER | BALANCE |
+----+-------+--------+---------+
| 1  | B0001 | 122960 | 100.00  |
+----+-------+--------+---------+
| 2  | B0001 | 123168 | -100.00 |
+----+-------+--------+---------+
| 3  | B0001 | 121400 | 500.00  |
+----+-------+--------+---------+
| 4  | T0001 | 19755  | 50.00   |
+----+-------+--------+---------+
| 5  | T0001 | 19975  | -50.00  |
+----+-------+--------+---------+
| 6  | T0001 | 122202 | 50.00   |
+----+-------+--------+---------+
| 7  | T0001 | 122203 | 50.00   |
+----+-------+--------+---------+

我正在尝试选择给定代码的余额可以与另一行偏移并总计为0的行。例如，第1行和第2行的余额总计为0，因此应返回。我已经尝试过以下查询：

SELECT T1.NUMBER
FROM TABLE T1,TABLE T2
WHERE T1.CODE = T2.CODE
AND T1.BALANCE + T2.BALANCE = 0

这对于代码B0001来说可以正常工作。它将返回第1行和第2行，它们彼此抵消，并忽略第3行。代码T0001出现问题，因为我使用的查询会将3个正值中的每一个与负值匹配，并返回所有关联的行该代码。我只希望它返回T0001的第4行和第5行。

解决方法

尝试一下：

/* DATASET MOCK-UP */
DECLARE @Data TABLE ( ID INT,CODE VARCHAR(10),NUMBER INT,BALANCE DECIMAL(18,2) );
INSERT INTO @Data ( ID,CODE,NUMBER,BALANCE ) VALUES
( 1,'B0001',122960,100.00 ),( 2,123168,-100.00 ),( 3,121400,500.00 ),( 4,'T0001',19755,50.00 ),( 5,19975,-50.00 ),( 6,122202,( 7,122203,50.00 );

/*
    Return records where combined balances equal 0 by adding the
    current record's BALANCE against its previous (lag) or following (lead) balances.
*/
SELECT
    ID,BALANCE,( BALANCE + LAG_BALANCE ) AS LAG_BALANCE,( BALANCE + LEAD_BALANCE ) AS LEAD_BALANCE
FROM (
    
    SELECT
        ID,LAG ( BALANCE,1,0 ) OVER ( PARTITION BY CODE ORDER BY CODE,ID ) AS LAG_BALANCE,LEAD ( BALANCE,ID ) AS LEAD_BALANCE 
    FROM @Data

) AS Results
WHERE
    BALANCE + LAG_BALANCE = 0
    OR
    BALANCE + LEAD_BALANCE = 0
ORDER BY
    ID;

+----+-------+--------+---------+-------------+--------------+
| ID | CODE  | NUMBER | BALANCE | LAG_BALANCE | LEAD_BALANCE |
+----+-------+--------+---------+-------------+--------------+
|  1 | B0001 | 122960 | 100.00  | 100.00      | 0.00         |
|  2 | B0001 | 123168 | -100.00 | 0.00        | 400.00       |
|  4 | T0001 |  19755 | 50.00   | 550.00      | 0.00         |
|  5 | T0001 |  19975 | -50.00  | 0.00        | 0.00         |
|  6 | T0001 | 122202 | 50.00   | 0.00        | 100.00       |
+----+-------+--------+---------+-------------+--------------+

更新：我只希望可以取消NUMBER个值。对于T0001，返回哪个数字以取消负值并不重要，只要它仅返回一对值即可。例如，对于T0001，它可以返回第4和5、5和6或5和7行。它们都有效，但是我只想要其中之一。

此修改为与您的“归零”条件匹配的每个CODE返回一个数字：

SELECT
    CODE,MIN ( NUMBER ) AS MIN_NUMBER
FROM (
    
    SELECT
        ID,ID ) AS LEAD_BALANCE 
    FROM @Data

) AS Results
WHERE
    BALANCE + LAG_BALANCE = 0
    OR
    BALANCE + LEAD_BALANCE = 0
GROUP BY
    CODE
ORDER BY
    CODE;

+-------+------------+
| CODE  | MIN_NUMBER |
+-------+------------+
| B0001 |     122960 |
| T0001 |      19755 |
+-------+------------+

更新＃2：

/*
    Return the first TWO rows for a CODE with BALANCEs that zero-out each other.
*/
SELECT
    ID,ID ) AS LEAD_BALANCE,ROW_NUMBER() OVER ( PARTITION BY CODE ORDER BY CODE,ID ) AS CODE_ROW
    FROM @Data

) AS Results
WHERE
    CODE_ROW <= 2
    AND ( BALANCE + LAG_BALANCE = 0 OR BALANCE + LEAD_BALANCE = 0 )
ORDER BY
    ID;

+----+-------+--------+---------+-------------+--------------+
| ID | CODE  | NUMBER | BALANCE | LAG_BALANCE | LEAD_BALANCE |
+----+-------+--------+---------+-------------+--------------+
|  1 | B0001 | 122960 | 100.00  | 100.00      | 0.00         |
|  2 | B0001 | 123168 | -100.00 | 0.00        | 400.00       |
|  4 | T0001 |  19755 | 50.00   | 50.00       | 0.00         |
|  5 | T0001 |  19975 | -50.00  | 0.00        | 0.00         |
+----+-------+--------+---------+-------------+--------------+

您想以相反的余额匹配行，但每行只能匹配一次。

一个选项是首先用row_number()枚举行。然后，您可以使用自联接解决方案，在联接条件中添加行号。我更喜欢not exists-但逻辑是相同的：

with  cte as (
    select 
        t.*,row_number() over(partition by code,balance order by id) rn
    from mytable t
)
select *
from cte c
where exists (
    select 1 
    from cte c1 
    where c1.code = c.code and c1.rn = c.rn and c1.balance + c.balance = 0
)
order by code,id

Demo on DB Fiddle ：

id | code  | number | balance | rn
-: | :---- | -----: | ------: | -:
 1 | B0001 | 122960 |  100.00 |  1
 2 | B0001 | 123168 | -100.00 |  1
 4 | T0001 |  19755 |   50.00 |  1
 5 | T0001 |  19975 |  -50.00 |  1

类似这样的东西

;with 
neg_cte as (select *,balance order by id) rn 
            from @Data where BALANCE<0),pos_cte as (select *,balance order by id) rn 
            from @Data where BALANCE>0)
select * from neg_cte
union all
select pc.* from neg_cte nc join pos_cte pc on nc.CODE=pc.CODE
                                            and nc.BALANCE=pc.BALANCE*-1
                                            and nc.rn=pc.rn
order by ID;

结果

ID  CODE    NUMBER  BALANCE rn
1   B0001   122960  100.00  1
2   B0001   123168  -100.00 1
4   T0001   19755   50.00   1
5   T0001   19975   -50.00  1

仅选择第一个反向重复

如何解决仅选择第一个反向重复

解决方法

相关推荐