Question

表错误和依赖关系如下所示：

select * from bugs; 
+--------+--------+
| bug_id | status |
+--------+--------+
|     20 | NEW    |
|     45 | CLOSED |
|     47 | NEW    |
|     30 | NEW    |
|     50 | CLOSED |
+--------+--------+


select * from dependencies;
+-----------+---------+
| dependson | blocked |
+-----------+---------+
|        20 |      45 |
|        20 |      47 |
|        30 |      50 |
+-----------+---------+

联接查询的预期结果：30

什么？从列依赖项，表依赖项中仅提取30，因为30是唯一（ NEW status ）阻止（col：blocked-50）状态为CLOSED的错误。尽管dependson条目20是阻塞45，它是CLOSED但是它也阻止了47，它没有被关闭。

注意：列依赖和阻止都是bug_id的外键。

我尝试了不同的查询，但仍无法获得正确的查询...有人可以帮忙吗？

更新：仅需要状态NEW并非全部。

Answer 1

尝试此查询 -

SELECT b.* FROM bugs b
  JOIN (
    SELECT
      d.*
    FROM dependencies d
      JOIN bugs b
        ON b.bug_id = d.blocked
    GROUP BY d.dependson
      HAVING COUNT(IF(status = 'CLOSED', status, NULL)) = COUNT(*)
  ) t
  ON b.bug_id = t.dependson

Answer 2

Select bugs.* From bugs Inner Join dependencies On (bugs.bug_id = dependencies.blocked) Where bugs.status = 'CLOSED' And bugs.bug_id = dependencies.blocked

实际上，您可能不需要and声明的where部分，但我无法对其进行测试，因此请将其放在那里以便进行测量。

修改

我刚看到你正在试图获得依赖而不是阻止。我会更新这个。

Select bugs.bug_id From bugs Inner Join dependencies On (bugs.bug_id = dependencies.dependedson) Where dependencies.dependson Not In (Select dependencies.dependson From bugs Inner Join dependencies On (bugs.bug_id = dependencies.blocked) Where bugs.status = 'New' And bugs.bug_id = dependencies.blocked) And bugs.bug_id = dependencies.dependson

Answer 3

它没有经过测试，但我认为你不需要在这里加入。

SELECT dependson 
FROM dependencies

WHERE dependson NOT IN
(SELECT bug_id FROM bugs WHERE status <> 'CLOSED')

通过这种方式，您只能获得已关闭的dependson。

mysql连接查询以提取仅阻止CLOSED错误的id

3 个答案: