Question

我以更简单的方式重述这个问题，因为我得到的评论过于具体：

根据以下旅行模式关系，如何在区域 X <中选择至少一个停止的所有行程 < / em>，仍然有查询返回行程的所有停止，即使其他停止位于区域< / strong>除了 X

我正在使用Php和MySQL以及Doctrine。

Region HAS MANY Country Country HAS MANY Area Area HAS MANY Property Property HAS MANY Stop Itinerary HAS MANY Stop

Answer 1

SELECT i.*
     , sa.*
FROM Itinerary AS i
  JOIN Stop AS sa
    ON i.ItineraryId = sa.ItineraryId
WHERE EXISTS
      ( SELECT *
        FROM Stop AS s
          JOIN Property AS p
            ON p.PropertyId = s.PropertyId
          JOIN Area AS a
            ON a.AreaId = p.AreaId
          JOIN Country AS c
            ON c.CountryId = a.CountryId 
          JOIN Region AS r
            ON r.RegionId  = c.RegionId
        WHERE s.ItineraryId = i.ItineraryId
          AND r.Name = @X
      )

Answer 2

从行程中选择* EXISTS（从行程中选择*停止= X）;

Answer 3

SELECT * from Itinerary where id in(
SELECT DISTINCT Itinerary.id
FROM Itinerary
LEFT JOIN Stop on Itinerary.something = Stop.something
LEFT JOIN Property ON Stop.something=Property.something
LEFT JOIN Area ON Area.something=Property.something
LEFT JOIN Country ON Country.something=Area.something
LEFT JOIN Region ON Region.something = Country.something
WHERE Region.something = X)

MySQL查询问题 - 加入和分组

3 个答案: