On Sat, Jun 23, 2007 at 10:33:49PM +0100, Gregory Stark wrote: > "Martijn van Oosterhout" <kleptog@xxxxxxxxx> writes: > > On Fri, Jun 22, 2007 at 07:38:01PM +0300, Tzahi Fadida wrote: > >> Let me simplify it in lamer terms. > >> Basically, you have a cycle in your relations schema. i.e. > >> rel A: att-x, att-y > >> rel B: att-y, att-z > >> rel C: att-z, att-x > > I'm still lost. I can see how it would be hard to join these together but I'm > not sure what result I would be after. Well, the way I understand it is if you had the following data: rel A x : y 1 : 2 5 : 6 rel B: y : z 2 : 3 7 : 8 rel C: z : x 3 : 1 10 : 9 That the result would be: x : y : z 1 : 2 : 3 5 : 6 : : 7 : 8 9 : : 10 Now, I can't off the top of my head think of a schema where you would need this, but if you have this problem then I don't see the solution in plain SQL. Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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