Sql 一对多查询元组

我有一个与实体2有一对多关系的实体1。 Entity2存储属性，并具有字段“key”和“value”

现在我需要查询所有具有特定键/值组合（和逻辑）的Entity1

用这个

SELECT some_filed FROM Entity1 AS e1 Join e1.props AS p 
WHERE 
(p.key = :key1 and p.value = :value1)
and
(p.key = :key2 and p.value = :value2);

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一种容易推广到更多键/值对的方法是使用条件聚合：

SELECT entity_id
FROM e.props
GROUP BY entity_id
HAVING SUM(CASE WHEN e2.key = :key1 and e2.value = :value1 THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN e2.key = :key2 and e2.value = :value2 THEN 1 ELSE 0 END) > 0;

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对于更多条件，您只需将更多子句添加到

having

JPA理解存在：

SELECT e1 FROM Entity1 e1 
WHERE exists (select 1 from Entity2 e2 
              where e2.entity1.id = e1.id
                and e2.key = :key1 and e2.value = :value1)
  AND exists (select 1 from Entity2 e2 
              where e2.entity1.id = e1.id
                and e2.key = :key2 and e2.value = :value2);

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可能是“e2.key=：key1和e2.value=：value1或e2.key=：key2和e2.value=：value2”@Multisync，它不会检查属性的组合。你看，这个查询不会为key1-key2返回任何东西，通常情况下是这样。@Dmitry:我只是尝试更正语法而不是逻辑。是我的查询错了吗？我想是的，甚至从语法的角度。。。[内部]JOIN语句应该包含ON子句：）抱歉，我错了，没有注意到“JPA”标记。但我仍然不明白您的查询如何确保两个不同的道具具有指定的值。我猜这是一个本机SQL查询。这是一个合适的JPQL查询，可以正常工作。从EsbErrorEntity中选择e1作为e1 Join e1.props e21 Join e1.props e22，其中e21.headerKey=：key1和e21.headerValue=：value1和e22.headerKey=：key2和e21.headerValue=：value2

SELECT entity_id
FROM e.props
GROUP BY entity_id
HAVING SUM(CASE WHEN e2.key = :key1 and e2.value = :value1 THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN e2.key = :key2 and e2.value = :value2 THEN 1 ELSE 0 END) > 0;

SELECT e1 FROM Entity1 e1 
WHERE exists (select 1 from Entity2 e2 
              where e2.entity1.id = e1.id
                and e2.key = :key1 and e2.value = :value1)
  AND exists (select 1 from Entity2 e2 
              where e2.entity1.id = e1.id
                and e2.key = :key2 and e2.value = :value2);