Sql 如何在引用特定列的行中测试一系列相等的X对行?
我正在使用SQLServer2008R2 按照PK DESC,考虑订单前20名的下表:Sql 如何在引用特定列的行中测试一系列相等的X对行?,sql,sql-server,sql-server-2008,Sql,Sql Server,Sql Server 2008,我正在使用SQLServer2008R2 按照PK DESC,考虑订单前20名的下表: PK SK VC APP M C == == == ==== == ================== 21 7 79 NULL 0 NULL 20 9 74 1 3 20=14, 18=13, 15=2 19 6 79 1 2 19=11, 17=7 18 9 77 1 0 NULL
PK SK VC APP M C
== == == ==== == ==================
21 7 79 NULL 0 NULL
20 9 74 1 3 20=14, 18=13, 15=2
19 6 79 1 2 19=11, 17=7
18 9 77 1 0 NULL
17 6 74 1 0 NULL
16 7 79 1 0 NULL
15 9 74 1 0 NULL
14 9 74 1 0 NULL
13 9 77 1 0 NULL
12 7 77 1 0 NULL
11 6 79 1 0 NULL
10 7 79 1 0 NULL
9 7 74 1 0 NULL
8 7 79 1 0 NULL
7 6 74 1 0 NULL
6 6 74 1 0 NULL
5 7 79 1 0 NULL
4 7 77 1 0 NULL
3 6 79 1 0 NULL
2 9 74 1 0 NULL
使用以下内容创建:
DECLARE @t TABLE(PK INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, SK INT NOT NULL, VC INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
INSERT @t (SK,VC,APP,M,C) VALUES
(7,77,1,0,NULL),
(9,74,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(6,74,1,0,NULL),
(7,79,1,0,NULL),
(7,74,1,0,NULL),
(7,79,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(9,77,1,0,NULL),
(9,74,1,0,NULL),
(9,74,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(9,77,1,0,NULL),
(6,79,1,2,'19=11, 17=7'),
(9,74,1,3,'20=14, 18=13, 15=2'),
(7,79,NULL,0,NULL)
我的任务是,如果APP所在的最新行不为NULL,则为匹配返回true
完成同一组同一当前SK的一系列X匹配对或最新行
例如,当仅测试2对时,如果当前所需的测试是在SK=6上进行的,那么一旦达到PK=19,就会出现匹配
匹配项为VC19=VC11=79和VC17=VC7=74
通过执行以下命令来查看:
DECLARE @PairsToTest int = 2
DECLARE @SK int = 6
SELECT
TOP (2*@PairsToTest)
*
FROM @t
WHERE
APP IS NOT NULL
AND SK = @SK
ORDER BY SK, PK DESC
结果:
PK SK VC APP M C
19 6 79 1 2 19=11, 17=7
17 6 74 1 0 NULL
11 6 79 1 0 NULL
7 6 74 1 0 NULL
另一个例子:
当测试3对时,当查看SK=9时,在PK=20上找到匹配项
虽然这本身就是一个有趣的问题,但对于我的任务来说,并没有必要测试所有的SKs。给定SK的结果对我来说就足够了
要查看匹配,请执行以下操作:
DECLARE @PairsToTest int = 3
DECLARE @SK int = 9
SELECT
TOP (2*@PairsToTest)
*
FROM @t
WHERE
APP IS NOT NULL
AND SK = @SK
ORDER BY SK, PK DESC
其结果是:
PK SK VC APP M C
20 9 74 1 3 20=14, 18=13, 15=2
18 9 77 1 0 NULL
15 9 74 1 0 NULL
14 9 74 1 0 NULL
13 9 77 1 0 NULL
2 9 74 1 0 NULL
如您所见:VC20=VC14=74、VC18=VC13=74和VC15=VC2
我考虑按正确的顺序选择所需的行集,并在VC中计算相等的行数。如果计数与@PairsToTest相同,则这是升起旗帜的标志
我试过:
DECLARE @PairsToTest int = 3
DECLARE @SK int = 9
;with t0 as
(
SELECT
TOP (2*@PairsToTest)
*
FROM @t
WHERE
APP IS NOT NULL
AND SK = @SK
ORDER BY SK, PK DESC
),
t1 AS
(
SELECT TOP (@PairsToTest) * FROM t0
),
t2 AS
(
SELECT TOP (@PairsToTest) * FROM t0 ORDER BY PK ASC
)
,t3 AS
(
SELECT TOP 99999999 * FROM t2 ORDER BY PK DESC
)
IF (SELECT COUNT(*) FROM t1 LEFT OUTER JOIN t3 ON t1.VC = t3.VC) = @PairsToTest
SELECT 1
ELSE
SELECT 0
但在这方面也有太多的缺陷:
VC不包含唯一的数据只是偶然的
不允许使用IF
我应该扔掉t3中排名靠前的9999999,尽管我可以接受
为了解决这个问题,我应该做哪些必要的更改?试试这段代码,它统计每个SK分区中的行对数,并从结果中排除没有行对的行:
DECLARE @t TABLE(PK INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, SK INT NOT NULL, VC INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
INSERT @t (SK,VC,APP,M,C) VALUES
(7,77,1,0,NULL),
(9,74,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(6,74,1,0,NULL),
(7,79,1,0,NULL),
(7,79,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(9,77,1,0,NULL),
(9,74,1,0,NULL),
(9,74,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(9,77,1,0,NULL),
(6,79,1,2,'19=11, 17=7'),
(9,74,1,3,'20=14, 18=13, 15=2'),
(7,79,NULL,0,NULL)
;WITH c AS
(
SELECT *,
DENSE_RANK() OVER (PARTITION BY SK ORDER BY VC DESC) DenseRankPartitionBySK,
ROW_NUMBER() OVER (PARTITION BY SK ORDER BY PK DESC) ordinalNumberInSKPartition
FROM @t
WHERE APP IS NOT NULL
),
e AS
(
SELECT *,
COUNT(*) OVER (PARTITION BY SK, DenseRankPartitionBySK) _Sum,
ROW_NUMBER() OVER (PARTITION BY SK, DenseRankPartitionBySK ORDER BY PK) Odd
FROM c
),
d AS (
SELECT *,
COUNT(*) OVER (PARTITION BY SK) numberOfRows
FROM e
WHERE _Sum % 2 = 0 OR Odd <> 1
)
SELECT
d.PK, d.SK, d.VC, d.APP, d.M, d.C,
CASE WHEN ordinalNumberInSKPartition = 1 THEN 1 ELSE 0 END IsTopRow,
numberOfRows / 2 [NumberOfPairsInSKPartition(M)]
FROM d
ORDER BY SK, PK DESC
你刚才让我头疼。。。
DECLARE @t TABLE(PK INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, SK INT NOT NULL, VC INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
INSERT @t (SK,VC,APP,M,C) VALUES
(7,77,1,0,NULL),
(9,74,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(6,74,1,0,NULL),
(7,79,1,0,NULL),
(7,74,1,0,NULL),
(7,79,1,0,NULL),
(6,79,1,0,NULL),
(7,77,1,0,NULL),
(9,77,1,0,NULL),
(9,74,1,0,NULL),
(9,74,1,0,NULL),
(7,79,1,0,NULL),
(6,74,1,0,NULL),
(9,77,1,0,NULL),
(6,79,1,2,'19=11, 17=7'),
(9,74,1,3,'20=14, 18=13, 15=2'),
(7,79,NULL,0,NULL)
DECLARE @PairsToTest int = 3
DECLARE @SK int = 9
IF ((SELECT COUNT(*) FROM @t WHERE APP IS NOT NULL AND SK = @SK)-@PairsToTest) >=0
BEGIN
DECLARE @swapData TABLE(PK1 INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, PK INT NOT NULL, SK INT NOT NULL, VC INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
DECLARE @olderData TABLE(PK2 INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, PK INT NOT NULL, SK INT NOT NULL, VC2 INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
DECLARE @newerData TABLE(PK3 INT NOT NULL IDENTITY(1,1) PRIMARY KEY CLUSTERED, PK INT NOT NULL, SK INT NOT NULL, VC3 INT NULL, APP INT NULL, M INT NOT NULL, C NVARCHAR(111) NULL);
INSERT @swapData SELECT TOP ((SELECT COUNT(*) FROM @t WHERE APP IS NOT NULL AND SK = @SK)-@PairsToTest) * FROM @t WHERE APP IS NOT NULL AND SK = @SK ORDER BY PK
INSERT @olderData SELECT TOP (@PairsToTest) PK,SK,VC,APP,M,C FROM @swapData ORDER BY PK1 DESC
INSERT @newerData SELECT TOP (@PairsToTest) * FROM @t WHERE APP IS NOT NULL AND SK = @SK ORDER BY SK, PK DESC
DECLARE @Matches int = (SELECT COUNT(*)FROM @newerData INNER JOIN @olderData ON PK2 = PK3 WHERE VC2=VC3)
IF @Matches = @PairsToTest
SELECT 1 AS Match
ELSE
SELECT 0 AS Match
END
ELSE
SELECT 0 AS Match
/*
SELECT TOP (2*@PairsToTest) * FROM @t WHERE APP IS NOT NULL AND SK = @SK ORDER BY SK, PK DESC
SELECT * FROM @olderData
SELECT * FROM @newerData
*/