Question

我正在处理一组本质上属于属性/值对的东西（实际上还有很多东西，但我为了这个问题而简化了）。你可以有效地将这些表格想象如下：

实体（EntityID，AttributeName，AttributeValue）PK = EntityID，AttributeName
目标（TargetID，AttributeName，AttributeValue）PK = TargetID，AttributeName

您如何使用SQL查询EntityID，TargetID的集合，其中Entity具有目标的所有属性以及相应的值？

编辑（根据要求提供DDL）：

CREATE TABLE Entities(
    EntityID INTEGER NOT NULL,
    AttributeName CHAR(50) NOT NULL,
    AttributeValue CHAR(50) NOT NULL,
    CONSTRAINT EntitiesPK PRIMARY KEY (EntityID,AttributeName)
);
CREATE TABLE Targets(
    TargetID INTEGER NOT NULL,
    AttributeName CHAR(50) NOT NULL,
    AttributeValue CHAR(50) NOT NULL,
    CONSTRAINT TargetsPK PRIMARY KEY (TargetID,AttributeName)
);

Answer 1

我喜欢这些问题，但我认为OP希望至少为表提供创建脚本甚至可能是一些示例数据并不是不合理的。

我喜欢听谁同意谁不同意。

Answer 2

好的，我想经过多次尝试和编辑后，这个解决方案终于有效了：

SELECT e1.EntityID, t1.TargetID
FROM Entities e1
  JOIN Entities e2 ON (e1.EntityID = e2.EntityID)
  CROSS JOIN Targets t1
  LEFT OUTER JOIN Targets t2 ON (t1.TargetID = t2.TargetID
    AND e2.AttributeName = t2.AttributeName
    AND e2.AttributeValue = t2.AttributeValue)
GROUP BY e1.EntityID, t1.TargetID
HAVING COUNT(e2.AttributeValue) = COUNT(t2.AttributeValue);

测试数据：

INSERT INTO Entities VALUES 
 -- exact same attributes, should match
 (1, 'Foo1', '123'),
 (1, 'Bar1', '123'),
 -- same attributes but different values, should not match
 (2, 'Foo2', '456'),
 (2, 'Bar2', '456'),
 -- more columns in Entities, should not match
 (3, 'Foo3', '789'),
 (3, 'Bar3', '789'),
 (3, 'Baz3', '789'),
 -- fewer columns in Entities, should match
 (4, 'Foo4', '012'),
 (4, 'Bar4', '012'),
 -- same as case 1, should match Target 1
 (5, 'Foo1', '123'),
 (5, 'Bar1', '123'),
 -- one attribute with different value, should not match
 (6, 'A', 'one'),
 (6, 'B', 'two');

INSERT INTO Targets VALUES 
 (1, 'Foo1', '123'),
 (1, 'Bar1', '123'),
 (2, 'Foo2', 'abc'),
 (2, 'Bar2', 'abc'),
 (3, 'Foo3', '789'),
 (3, 'Bar3', '789'),
 (4, 'Foo4', '012'),
 (4, 'Bar4', '012'),
 (4, 'Baz4', '012'),
 (6, 'A', 'one'),
 (6, 'B', 'twox');

测试结果：

+----------+----------+
| EntityID | TargetID |
+----------+----------+
|        1 |        1 | 
|        4 |        4 | 
|        5 |        1 | 
+----------+----------+

要回复您的评论，这里是一个反向表格的查询：

SELECT e1.EntityID, t1.TargetID
FROM Targets t1
  JOIN Targets t2 ON (t1.TargetID = t2.TargetID)
  CROSS JOIN Entities e1
  LEFT OUTER JOIN Entities e2 ON (e1.EntityID = e2.EntityID
    AND t2.AttributeName = e2.AttributeName
    AND t2.AttributeValue = e2.AttributeValue)
GROUP BY e1.EntityID, t1.TargetID
HAVING COUNT(e2.AttributeValue) = COUNT(t2.AttributeValue);

这是输出，给定上面相同的输入数据。

+----------+----------+
| EntityID | TargetID |
+----------+----------+
|        1 |        1 |
|        3 |        3 |
|        5 |        1 |
+----------+----------+

Answer 3

SELECT  *
FROM    (
    SELECT  eo.total,
        (
        SELECT  COUNT(*)
        FROM    Entities e, Targets t
        WHERE   e.EntityID = eo.EntityID
            AND t.TargetID = e.EntityID
            AND t.AttributeName = e.AttributeName
            AND t.AttributeValue = e.AttributeValue
        ) AS equal
    FROM    (
        SELECT  e.EntityID, COUNT(*) as total
        FROM    Entities e
        GROUP BY
            e.EntityID
        ) eo
    )
WHERE   total = equal

Answer 4

select distinct entityid,targetid
from   entities ent
,      targets  tar
where  not exists  
       (  select attributename, AttributeValue 
          from   targets  tar2
          where  tar.targetid = tar2.targetid
          minus
          select attributename, AttributeValue 
          from   entities  ent2
          where  ent2.entityid = ent.entityid)
and    not exists  
       (  select attributename, AttributeValue 
          from   entities  ent2
          where  ent2.entityid = ent.entityid
          minus 
          select attributename, AttributeValue 
          from   targets  tar2
          where  tar.targetid = tar2.targetid)
order by entityid,targetid
/

edit1：

如果目标表中的行在实体表中没有匹配是可以的，则解决方案简化为：

select distinct entityid,targetid
from   entities ent
,      targets  tar
where  not exists  
       (  select attributename, AttributeValue 
          from   entities  ent2
          where  ent2.entityid = ent.entityid
          minus 
          select attributename, AttributeValue 
          from   targets  tar2
          where  tar.targetid = tar2.targetid)
order by entityid,targetid
/

编辑2：

要理解OP的确切要求并不容易。

这是一个新的select语句。我希望他会测试我所有的选择陈述以理解差异。我希望他有很好的测试用例并知道他想要什么。

select distinct entityid,targetid
from   entities ent
,      targets  tar
where  not exists  
       (  select attributename, AttributeValue 
          from   targets  tar2
          where  tar.targetid = tar2.targetid
          minus  
          select attributename, AttributeValue 
          from   entities  ent2
          where  ent2.entityid = ent.entityid)
order by entityid,targetid
/

基于一组命名属性/值进行查询

4 个答案: