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Create a tree from a resultset

 
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Hi,

I need to create a tree structure from a resultset and show them into my JSP. Here is my table sql (grup).



What I really need is a recursive method to search for all the children of each row and build a tree heirarchy. e.g. the data may look like




So looking at the top data my final tree structure should look like


and so on. ORDER_BY show the order in which each element should display in the heirarchy. I am really struggling to find a way on how to have the heirarchy built and really need some help.

Thanks


Here is the SQL i have to het the data


 
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I usually use a Map for this. Something like this (pseudo code):
When done roots contains all root nodes. If you have one single tree it should contain only one element.
 
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