Re: Conflicts in Relationships

Jan, it appears something must be missing in our algorithm. I had no problem implementing it and I put a print statement in place of the check of the join condition. That way I can see that I'm walking the nodes correctly.

> You said......all the join conditions have to be full on both
> sides, i.e., they have to be *full* outer joins. All other join
> conditions only have to full on one side.

>

.. that seems true for the algorithm but not for SQL FROM clauses I'm trying to model. The join conditions can be Inner, Outer, Left, or Right. For example, in my 3 table query above join conditions like these denote a valid query:

A Left Join C

C Inner Join B

A Left Join B

In my code I load the 3 tables and 6 edges (3 edges in both directions) and I walk the graph with this output:

(TableA,TableC) Left Outer Join

• (TableC,TableB) Inner Join

(TableA,TableB) Left Outer Join

At the asterisks the code would have stopped to report a conflict. Am I doing somethng wrong or do we need somethin more complex to handle the 4 possible states of a join? Any ideas?

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