Aklakan commented on issue #3040:
URL: https://github.com/apache/jena/issues/3040#issuecomment-2690151251
Regarding
```sparql
VALUES ?a { :q }
BIND(?newA AS ?b)
```
With latest Jena, you can no longer re-bind variables in the Jena
implementation which is consistent with the [SPARQL 1.1 Spec Section
10](https://www.w3.org/TR/sparql11-query/#assignment).
Also, the ElementTransform code has undergone several fixes in the meantime.
In your case, QueryTransformOps.transform by now refuses to rename the
variable because it rejects the scoping.
```java
String queryString = """
PREFIX : <http://example/>
SELECT ?a WHERE {
VALUES ?a { :q }
}
""";
Map<Var, Var> varMap = new HashMap<>();
varMap.put(Var.alloc("a"), Var.alloc("newA"));
Query newQuery = QueryTransformOps.replaceVars(query, varMap);
System.out.println(newQuery);
```
gives
```
Exception in thread "main"
org.apache.jena.sparql.syntax.syntaxtransform.QueryScopeException: Can not use
?a in this query
at
org.apache.jena.sparql.syntax.syntaxtransform.QuerySyntaxSubstituteScope.reject(QuerySyntaxSubstituteScope.java:68)
at
org.apache.jena.sparql.syntax.syntaxtransform.QuerySyntaxSubstituteScope.checkAssignment(QuerySyntaxSubstituteScope.java:64)
```
@afs should this be the case?
What does work, is going through the algebra:
```java
String queryString = """
PREFIX : <http://example/>
SELECT ?a WHERE {
VALUES ?a { :q }
}
""";
Map<Var, Var> varMap = new HashMap<>();
varMap.put(Var.alloc("a"), Var.alloc("newA"));
Query query = QueryFactory.create(queryString,
Syntax.syntaxSPARQL_11);
Op op = Algebra.compile(query);
Op newOp = NodeTransformLib.transform(new
NodeTransformSubst(varMap), op);
Query newQuery = OpAsQuery.asQuery(newOp);
System.out.println(newQuery);
```
Output:
```
SELECT ?newA
WHERE
{ VALUES ?newA { <http://example/q> } }
```
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
