Mysql從同一個父表中連接多個列

Question

我有跟隨mysql查詢的問題。

給出2個表

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人

Id | 名稱

1 | 約翰·多伊

2 | 簡·多伊

3 | 冥王星

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門票

Id | 所有者| 開瓶器| 分配給

1 | 1 | 2 | 3

2 | 3 | 1 | 2

所有者，開啟者，AssignedTo是鏈接到People Id的外鍵

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我需要使用用戶名進行查詢替換Owner，Opener，AssignedTo列。

只有一列（它足以使用左連接）不是問題，但我無法接收以下輸出

select * from ....

1 | John Doe Jane Doe | 冥王星

2 | 冥王星| John Doe 簡·多伊

提前致謝。

Answer 1

你可以多次加入Person 。

SELECT t1.Id, t2.Name AS owner, t3.Name AS opener, t4.Name AS assignedTo
FROM Tickets t1
LEFT JOIN Person t2 ON t1.Owner = t2.Id
LEFT JOIN Person t3 ON t1.Opener = t3.Id
LEFT JOIN Person t4 ON t1.AssignedTo= t4.Id

Answer 2

選擇門票。 Id ，POwner.Name AS所有者，POpener.Name AS Opener，PAssignedTo.Name AS AssignedTo FROM Tickets JOIN Person AS POwner ON Owner = POwner.Id JOIN Person AS POpener ON Opener = POpener.Id JOIN Person as PAssignedTo ON AssignedTo = PAssignedTo。 ID