Details
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Task
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Status: Open (View Workflow)
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Trivial
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Resolution: Unresolved
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None
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None
Description
As described in the example documentation: https://mariadb.com/kb/en/library/oqgraph-examples/
I find it very useful to add the previous linked node in the sequence result when querying the graph:
SELECT * FROM oq_graph g |
WHERE g.latch='dijkstras' AND g.origid=1; |
| latch | origid | destid | weight | seq | linkid | previd |
|---|---|---|---|---|---|---|
| dijkstras | 1 | NULL | 4 | 6 | 5 | 4 |
| dijkstras | 1 | NULL | 3 | 5 | 4 | 3 |
| dijkstras | 1 | NULL | 2 | 4 | 6 | 2 |
| dijkstras | 1 | NULL | 2 | 3 | 3 | 2 |
| dijkstras | 1 | NULL | 1 | 2 | 2 | 1 |
| dijkstras | 1 | NULL | 0 | 1 | 1 | NULL |
That helps to implement relationship types and restrict them in the query like:
SELECT * FROM people_graph g |
JOIN people_relationships d ON d.destid = g.linkid AND d.origid = g.previd |
WHERE g.latch='dijkstras' |
AND g.origid=1 |
AND d.relationship='friendship'; |
Which only shows friends and friends of friends, but no family members.