>>Another example where sql is out of the game:
>>Build a database where the data they represent a connected graph ( not a treeview ).
>>Now, tries to extract the set of all row paths between two points with SQL commands.
>
>Known as the "travelling salesman problem"?
>
>Interesting. How do you represent the graph in your database and why is sql out of the game then?
>

If the nodes are homogenous
- a node it is a row of a table
then it is simple:
a table Arches with 3 columns
id is PK, RKid, FKid where (RKid, FKid) is candidate

try

CREATE CURSOR nodes (id I DEFAULT RECCOUNT()+1, tx c(20) DEFAULT TRANSFORM(id,"@R Nodes99999"))
FOR k=1 TO 5
	APPEND BLANK
NEXT
CREATE CURSOR Arches (id I,RKid I,FKid I)
INSERT INTO Arches (1,1,1)
INSERT INTO Arches (1,2,2)
INSERT INTO Arches (1,5,5)
INSERT INTO Arches (1,1,2)
INSERT INTO Arches (1,2,4)
INSERT INTO Arches (1,1,3)
INSERT INTO Arches (1,1,5)
INSERT INTO Arches (1,5,3)
INSERT INTO Arches (1,4,5)

* write a selects program that return the cursor PathNodes(1,5)=[1,2,4,5]

>Bye, Olaf.