is, there is some method to iterate in this relation to avoid joining the table in itself each time ?
Exactly the problem with trying to model an anything-goes network, a "world of ends", in a relational model of a directed graph. I think you need an XML layer in there, eg see http://iswc2004.semanticweb.org/demos/03/.
PB
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listsql listsql wrote:
Since I read about Foaf [ http://www.foaf-project.org/ ], I become interested with Social Networking, and readed a lot about it. I 've been playing as well with mysql and join querys to represent network's of people. As I made some queries in google and didn't came with a lot interesting info about this, now I will comment here my own querys.
urelation table: (this kind of relation is called the adjacency list model, or recursion) +-----+-----+ | uid | fid | +-----+-----+ | 1 | 2 | | 2 | 3 | | 1 | 3 | | 3 | 2 | | 3 | 0 | | 0 | 2 | | 3 | 1 | +-----+-----+ This represent's the id of people and the id of their friend ('s)
uprofile table: +-----+-----------+
| uid | name |
+-----+-----------+
| 0 | martin 0 |
| 1 | pedro 1 |
| 2 | pablo 2 |
| 3 | matias 3 |
| 4 | mateo 4 |
| 5 | claudio 5 |
+-----+-----------+
So if I want to get the friend's and friend's of friend's of pablo:
SELECT p1.name p1,p2.name p2
FROM uprofile p1,uprofile p2
left join urelation r1 ON r1.fid=p1.uid and r1.uid =2 left join urelation r2 ON r2.fid=p2.uid where r2.uid =r1.fid
+----------+----------+ | p1 | p2 | +----------+----------+ | matias 3 | martin 0 | | matias 3 | pedro 1 | | matias 3 | pablo 2 | +----------+----------+
And I add logically one join more if I want to get deeper in the network. The obvious problem is that for the first table p1 I will get the repeating Id, but that is not an issue now.
Where I wanted to get more feedback is, there is some method to iterate in this relation to avoid joining the table in itself each time ? Or also: Is this the best way to store human-like social relations, or there is a better way to do this ?
Thanks in advance,
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