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From:Matt Juszczak Date:June 19 2007 8:58am
Subject:Storing a linked list
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Hi all,

I've got a table such as the following:

id1 char
id2 char

sample data looks like this:

id1	id2
1	3
2	4
3	5
5	6
6	8

And of course another table has something like:

id	info1	info2	info3
1	blah	blah	blah
2	blah	blah	blah

I'd like to store paths to specific destinations...

In other words, the path from 1 to 8 is:


I was thinking of creating a table called relationships

start	end	path
1	8	{3,5,6}

This would allow me to easily display the path if I know the start and end, but 
what it doesn't allow me to do is reuse the data.

IE: say that I calculate the path from 1 to 8 as 1,3,5,6,8, and then I want to 
know the path from 3 to 6.  even though this is already calculated, I have to 
recalculate it as another row... hence

start	end	path
1	8	{3,5,6}
3	6	{5}

I considered making another table, called hops, such as:

start	end	relationshipID
1	8	1

table hops:
relationshipID	start	end
1		1	3
1		3	5
1		5	6
1		6	8

Then I could almost "reuse" those hops somehow.... but not sure.

Can anyone recommend a good way to store this data?


Storing a linked listMatt Juszczak19 Jun
  • Re: Storing a linked listMogens Melander19 Jun
  • Re: Storing a linked listPeter Brawley19 Jun
    • Re: Storing a linked listBaron Schwartz19 Jun