Jump to content

order by problem. Like to order it as a folder tree structure


Recommended Posts

I'm having troubles ordering my table as a folder tree structure. Who can help me out here?

(Assume i have the newest Mysql version. To keep the example easy to look at, the messages just say 'bla bla')

 

I have the following table:

IDMessagechild_from

------------------

0bla blaNULL

1bla blaNULL

2bla bla0

3bla bla1

4bla bla1

5bla bla0

6bla blaNULL

7bla bla3

8bla bla4

9bla bla8

 

I'd like to order the table in such a way, that it would become like this:

 

IDMessagechild_from

------------------

0bla blaNULL

2bla bla0

5bla bla0

1bla blaNULL

3bla bla1

7bla bla3

4bla bla1

8bla bla4

9bla bla8

6bla blaNULL

 

How do i do that with just one Query??

 

the goal is to create something like this:

0 bla bla

-- 2 bla bla

-- 5 blabla

1 bla bla

-- 3 bla bla

---- 7 bla bla

-- 4 bla bla

----8 bla bla

------9 blabla

6 bla bla

 

I'm not sure if this is possible in MySQL alone... the way I'd approach this problem is by creating a recursive function in PHP that checks to see:

 

A. if the message is a top level category.

B. if there are children to that category.

 

Just recently, I read about this very subject in a book that shows how to handle this situation. When i get home and if this problem is unresolved, ill share the example.

well, actually i'm ordering by something that isn't really there. As you can see i started by taking the lowest ID without a 'child_from'. Then there is the lowest ID row with child_from='0' (this happens to be ID=2), Then, because there is no child_from='2', it searches for child_from='0' again, etc etc

 

Because i'm ordering by something that isn't there, i've been thinking about (and trying to make) a additional column with AS in the mysql statement. But i haven't succeeded so far and i'm not sure it's the way to do it.

This thread is more than a year old. Please don't revive it unless you have something important to add.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.