On 10/03/13 02:19, Diogo FC Patrao wrote:
Hello
I'm studying doing transformations in SPARLQ queries; based on this [1]
tutorial, I wrote the code below.
teste.main() was supposed to print a query specifiying ":teste3" instead of
":teste1" (that`s what my QueryExpander was supposed to do), however the
two printed algebras are identical!
I thought that when the QueryExpander.transform method would return
something else than the original opBGP, it would be substituted on the
algebra. I couldn't find any other example other than [1].
Any help would be greatly appreciated.
dfcp
----
Two points:
public class QueryExpander extends TransformBase {
That should be
..... extends TransformCopy
which is why you are seeing no change. As you have it you make aone
level change, but it's not copied back up the tree.
Also,
public Op transform(OpBGP opBGP) {
// TODO Auto-generated method stub
BasicPattern x = opBGP.getPattern();
BasicPattern opNewPattern = new BasicPattern();
for( int i =0; i< x.size(); i++ ) {
opNewPattern.add( transform(x.get(i)) );
}
Op newOpBGP = new OpBGP( );
return newOpBGP;
}
You haven't connected the opNewPattern with newOpBGP
Try:
Op newOpBGP = new OpBGP( opNewPattern );
Andy
