MySQL：根据已选择行中的值选择行

Question

我想根据已选择的行中的值从数据库中的连接表中选择行。基本上，如果父行或祖父行处于活动状态，则还要在结果中包含子行或孙行。

我尝试使用 JOINS 和 UNIONS 的不同组合来获得我想要的结果，但没有成功。

这是我的示例数据：

表 1：目标 （可供成员设定为目标或完成的目标）

id   | name     | parent
---------------------------
A    | Obj A    | null 
A1   | Obj A1   | A 
A2   | Obj A2   | A
A2-1 | Obj A2.1 | A2
B    | Obj B    | null
B1   | Obj B1   | B
B1-1 | Obj B1.1 | B1
C    | Obj C    | null
C1   | Obj C1   | C
C1-1 | Obj C1.1 | C1

表 2：成员目标 （目标成员已经完成或设定为目标）

id | objective | member | status
-----------------------------------
1  | A         | 001    | goal
2  | A1        | 001    | complete
3  | C         | 001    | goal

所需结果： 连接两个表并选择状态为 goal 或 complete 或父或祖父目标状态为 goal 或 complete 的所有行。

objective | member | name     | status
------------------------------------------
A         | 001    | Obj A    | goal
A1        | 001    | Obj A1   | complete
A2        | 001    | Obj A2   | null
A2-1      | 001    | Obj A2-1 | null
C         | 001    | Obj C    | goal
C1        | 001    | Obj C1   | null
C1-1      | 001    | Obj C1.1 | null

A2 和C2 被包括在内，因为他们的父母A 和C 的状态为goal 和A2-1 和C1-1 被包括在内，因为他们的祖父母的状态为@ 987654337@。不包括B 及其子目标和孙目标，因为memberObjectives 表中没有B 的状态为complete 或goal。

我最近的尝试，我知道还没有接近如下：

SELECT DISTINCT mo.objective, mo.member, o.name, mo.status 
  FROM objectives AS o
  LEFT JOIN (SELECT * FROM memberObjectives 
    WHERE member = '001') AS mo ON o.id = mo.objective
  LEFT JOIN objectives AS o2 ON o2.id = o.parent
  LEFT JOIN objectives AS o3 ON o3.id = o2.parent 
  GROUP BY o.id

感谢您提供的任何帮助！

Answer 1

无法测试，但试试这个：

SELECT mo.objective, mo.member, o.name, mo.status 
  FROM objectives AS o
  LEFT JOIN memberObjectives o.id=mo.objetive
WHERE status='goal' or status='complete'
OR o.id IN(select parent from objetives o inner join memberObjectives mo on o.parent=mo.objetive WHERE status='goal' or status='complete')

这应该为您提供状态目标或完成的记录以及父母拥有该记录的记录。我由你决定将它扩展到祖父。希望对您有所帮助。

Answer 2

三个查询供您查看：请参阅FIDDLE 了解工作示例

如果您可以通过作为 A 的 id 进行过滤，那么此查询将完全按照您的要求进行。

SELECT t.id as objective, mo.member, t.name, mo.status from(
  SELECT * FROM objective o
)AS t
LEFT JOIN memberObjective mo ON mo.objective = t.id
WHERE t.id in(SELECT objective FROM memberObjective)
OR t.parent in(SELECT o.id FROM objective o where o.id like "%A%")

此查询获取父级，但不获取祖父级。

SELECT t.id as objective, mo.member, t.name, mo.status from(
  SELECT * FROM objective o
)AS t
LEFT JOIN memberObjective mo ON mo.objective = t.id
WHERE t.id in(SELECT objective FROM memberObjective)
OR t.parent in(SELECT o.id FROM objective o join memberObjective mo on mo.objective = o.id)

此查询获取父母和祖父母，但它没有过滤掉 B.. 数据库中没有足够的数据来添加祖父母，因为 A2 在您的表中只出现两次，并且它的父母和 id .

SELECT t.id as objective, mo.member, t.name, mo.status from(
  SELECT * FROM objective o
)AS t
LEFT JOIN memberObjective mo ON mo.objective = t.id
WHERE t.id in(SELECT objective FROM memberObjective)
OR t.parent in(SELECT o.id FROM objective o left join memberObjective mo on mo.objective = o.id) 
----  you could add LIMIT 4 to get the correct results but thats another semi hacky way to do it

Answer 3

我创建了一个目前似乎可行的解决方案。它添加了更多连接，以在每一行中包含 parentStatus 和 grandparentStatus 列。现在，如果 status、parentStatus 或 grandparentStatus 为 goal 或 complete，则该行将包含在结果中。

下面的 MySQL 查询结果如下：

objective | member | name     | status    | parentStatus | grandparentStatus
------------------------------------------------------------------------------
A         | 001    | Obj A    | goal      | null         | null
A1        | 001    | Obj A1   | complete  | goal         | null
A2        | 001    | Obj A2   | null      | goal         | null
A2-1      | 001    | Obj A2-1 | null      | null         | goal
C         | 001    | Obj C    | goal      | null         | null
C1        | 001    | Obj C1   | null      | goal         | null
C1-1      | 001    | Obj C1.1 | null      | null         | goal

这是 MySQL 查询：

SELECT DISTINCT * FROM objectives AS o  
  LEFT JOIN (SELECT * FROM memberObjectives WHERE member = '001') 
    AS mo ON mo.objective = o.id 
  LEFT JOIN (SELECT mo2.status AS parentStatus, mo2.objective AS parentObjective
    FROM memberObjectives AS mo2
    LEFT JOIN objectives AS o2 ON o2.parent = mo2.objective 
    WHERE mo2.member = '001') 
      AS parent ON parent.parentObjective = o.parent
  LEFT JOIN (SELECT mo3.status AS grandparentStatus, mo3.objective AS grandparentObjective 
    FROM memberObjectives AS mo3
    LEFT JOIN objectives AS o3 ON o3.parent = mo3.objective 
    WHERE mo3.member = '001') 
      AS grandparent ON grandparent.grandparentObjective = o.parent
  WHERE mo.status = 'goal' OR mo.status = 'complete' 
    OR parentStatus = 'goal' OR parentStatus = 'complete' 
    OR grandparentStatus = 'goal' OR grandparentStatus = 'complete' 
  GROUP BY o.id

根据我最初的问题，解决方案不是根据已选择行中的值选择行，而是连接表以具有额外的列来检查来自其他行的必要值。