Question

I’m having following problem with mysql query.

Given 2 tables

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Person

Id | Name

1 | John Doe

2 | Jane Doe

3 | Pluto

---

Tickets

Id | Owner | Opener | AssignedTo

1 | 1 | 2 | 3

2 | 3 | 1 | 2

Owner, Opener, AssignedTo are Foreign keys linking to People Id

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I need to make a query replacing Owner, Opener, AssignedTo columns with user names.

It’s not a problem with just one column (it’s enough to use left join), but I can’t receive following output

select * from ….

1 | John Doe | Jane Doe | Pluto

2 | Pluto | John Doe | Jane Doe

Thanks in advance.

Answer 1

You could join Person multiple times.

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