Question

我正在尝试将两个数据库合并到同一个模式中，这是其中的一部分。

我已经改变主题以使其更容易理解 - 我无法改变这个架构，这正是我正在使用的。

我的源数据库和目标数据库中都有一个表，其中包含以下列：

Car
CarType1
CarType2
CarType3
CarType4

我正在尝试编写一个查询，告诉我在目标数据库中，哪些行在两个数据库之间具有相同的汽车，但是不同的CarTypes。我只需要计算不同的行。

我用英语写的查询将是：带回一些行数，其中Car是相同的，并且两个系统之间的CarTypes不匹配。如果CarType位于两者之间的不同CarType字段中，则无关紧要，只是所有值是否包含在4个字段之一中。

所以如果在我的源数据库中这一行：

Car: Mustang
CarType1: Fast
CarType2: Convertible
CarType3: null
CarType4: null

在我的目标数据库中，我有这一行：

Car: Mustang
CarType1: Fast
CarType2: Convertible
CarType3: Sports
CarType4: null

这将被视为不匹配，因为它是野马，并且因为CarType字段的聚合不同。这些值的顺序与此无关。

我该如何撰写此查询？我无法掌握它。

Answer 1

试试这个并告诉我它是否有效：

SELECT * FROM db1.dbo.Cars
EXCEPT
SELECT c1.* FROM db1.dbo.Cars as c1
INNER JOIN db2.dbo.Cars as c2
ON    c1.Car = c2.Car
      AND
      --Check carType1
      (c1.CarType1 = c2.CarType1 OR 
      c1.CarType1 = c2.CarType2 OR 
      c1.CarType1 = c2.CarType3 OR 
      c1.CarType1 = c2.CarType4) 
      AND
      --Check carType2
      (c1.CarType2 = c2.CarType1 OR 
      c1.CarType2 = c2.CarType2 OR 
      c1.CarType2 = c2.CarType3 OR 
      c1.CarType2 = c2.CarType4)
      AND
      --Check carType3
      (c1.CarType3 = c2.CarType1 OR 
      c1.CarType3 = c2.CarType2 OR 
      c1.CarType3 = c2.CarType3 OR 
      c1.CarType3 = c2.CarType4)
      AND
      --Check carType4
      (c1.CarType4 = c2.CarType1 OR 
      c1.CarType4 = c2.CarType2 OR 
      c1.CarType4 = c2.CarType3 OR 
      c1.CarType4 = c2.CarType4)

注意：

如果列为空，则必须向此添加ISNULL以包含或排除。

要排除：

ISNULL(c1.CarType4, -1) = ISNULL(c2.CarType4, -2)

包括：

ISNULL(c1.CarType4, -1) = ISNULL(c2.CarType4, -1)

Answer 2

;WITH SourceT AS (
SELECT 'Toyota' AS Car, 'A' AS CarType1, 'B' AS CarType2, 'C' CarType3, 'D' CarType4 UNION ALL
SELECT 'BMW' AS Car, 'A' AS CarType1, 'B' AS CarType2, 'C' CarType3, 'D' CarType4 UNION ALL
SELECT 'Mustang' AS Car, 'Fast' AS CarType1, 'Convertible' AS CarType2, 'Sports' CarType3, NULL CarType4 
),
TargetT AS (
SELECT 'Toyota' AS Car, 'D' AS CarType1, 'C' AS CarType2, 'B' CarType3, 'A' CarType4 UNION ALL
SELECT 'BMW' AS Car, 'D' AS CarType1, 'C' AS CarType2, 'B' CarType3, 'A' CarType4  UNION ALL
SELECT 'Mustang' AS Car, 'Fast' AS CarType1, 'Convertible' AS CarType2, NULL CarType3, NULL CarType4 )

SELECT *
FROM SourceT s
WHERE NOT EXISTS
(
SELECT * 
FROM TargetT t 
WHERE s.Car = t.Car AND 0 =
(SELECT COUNT(*) FROM 
    ( (
       (SELECT s.CarType1 AS t UNION ALL 
        SELECT s.CarType2 AS t UNION ALL 
        SELECT s.CarType3 AS t UNION ALL 
        SELECT s.CarType4 AS t )
    EXCEPT                
       (SELECT t.CarType1 AS t UNION ALL 
        SELECT t.CarType2 AS t UNION ALL 
        SELECT t.CarType3 AS t UNION ALL 
        SELECT t.CarType4 AS t )
        ) 
    UNION ALL
    (
       (SELECT t.CarType1 AS t UNION ALL 
        SELECT t.CarType2 AS t UNION ALL 
        SELECT t.CarType3 AS t UNION ALL 
        SELECT t.CarType4 AS t )
    EXCEPT                
       (SELECT s.CarType1 AS t UNION ALL 
        SELECT s.CarType2 AS t UNION ALL 
        SELECT s.CarType3 AS t UNION ALL 
        SELECT s.CarType4 AS t )
        )     
        ) T
    )
)

或稍短的版本

SELECT *
FROM SourceT s
WHERE NOT EXISTS
(
SELECT * 
FROM TargetT t 
WHERE s.Car = t.Car AND 
(SELECT t FROM (SELECT s.CarType1 AS t UNION ALL 
                SELECT s.CarType2 AS t UNION ALL 
                SELECT s.CarType3 AS t UNION ALL 
                SELECT s.CarType4 AS t ) D ORDER BY t FOR XML PATH(''))=
(SELECT t FROM (SELECT t.CarType1 AS t UNION ALL 
                SELECT t.CarType2 AS t UNION ALL 
                SELECT t.CarType3 AS t UNION ALL 
                SELECT t.CarType4 AS t ) D ORDER BY t FOR XML PATH(''))
    )

Answer 3

SELECT c1.car
FROM target.cars c1
INNER JOIN source.cars c2
ON c2.car = c1.car
WHERE
COALESCE( c1.cartype1, '') NOT IN 
( '', c2.cartype1, c2.cartype2, c2.cartype3, c2.cartype4 )
OR
COALESCE( c1.cartype2, '') NOT IN 
( '', c2.cartype1, c2.cartype2, c2.cartype3, c2.cartype4 )
OR
COALESCE( c1.cartype3, '') NOT IN 
( '', c2.cartype1, c2.cartype2, c2.cartype3, c2.cartype4 )
OR
COALESCE( c1.cartype4, '') NOT IN 
( '', c2.cartype1, c2.cartype2, c2.cartype3, c2.cartype4 )
OR
LEN( COALESCE( c1.cartype1, '') + COALESCE( c1.cartype2, '') +
 COALESCE( c1.cartype3, '') + COALESCE( c1.cartype4, '') ) 
<>
LEN( COALESCE( c2.cartype1, '') + COALESCE( c2.cartype2, '') + COALESCE( c2.cartype3, '') + 
COALESCE( c2.cartype4, '') )
;

以不同顺序查找多列中的匹配项

3 个答案: