[
https://issues.apache.org/jira/browse/JENA-1487?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Claus Stadler updated JENA-1487:
--------------------------------
Description:
Ordering an empty result set must not introduce additional bindings, but this
happens with the following example (run on an arbitrary dataset - including an
empty one):
{code:bash}
./fuseki-server --file=test.ttl /foobar
{code}
The Json below is obtained from the Fuski bundle; but I noted this issue first
using the ARQ API, where the result set contains a single BindingProjectNamed
instance.
{code:sql}
SELECT ?s
WHERE {
?s ?p ?o
FILTER(false)
}
GROUP BY ?s
ORDER BY DESC(COUNT(?o))
{code}
{code:json}
{
"head": {
"vars": [ "s" ]
} ,
"results": {
"bindings": [
{
# NOTE THIS EMPTY BINDING HERE!
}
]
}
}
{code}
The result set is correct without the ORDER BY:
{code:sql}
SELECT ?s
WHERE {
?s ?p ?o
FILTER(false)
}
GROUP BY ?s
{code}
{code:json}
{
"head": {
"vars": [ "s" ]
} ,
"results": {
"bindings": [
# CORRECT
]
}
}
{code}
was:
Ordering an empty result set must not introduce additional bindings, but this
happens with the following example (run on an arbitrary dataset - including an
empty one):
{code:bash}
./fuseki-server --file=test.ttl /foobar
{code}
The Json below is obtained from the Fuski bundle; I could figure out that using
the ARQ API, the result set contains a single BindingProjectNamed instance, but
I did not investigate any deeper.
{code:sql}
SELECT ?s
WHERE {
?s ?p ?o
FILTER(false)
}
GROUP BY ?s
ORDER BY DESC(COUNT(?o))
{code}
{code:json}
{
"head": {
"vars": [ "s" ]
} ,
"results": {
"bindings": [
{
# NOTE THIS EMPTY BINDING HERE!
}
]
}
}
{code}
The result set is correct without the ORDER BY:
{code:sql}
SELECT ?s
WHERE {
?s ?p ?o
FILTER(false)
}
GROUP BY ?s
{code}
{code:json}
{
"head": {
"vars": [ "s" ]
} ,
"results": {
"bindings": [
# CORRECT
]
}
}
{code}
> Incorrect SPARQL query result set when applying ORDER BY after an empty GROUP
> BY
> --------------------------------------------------------------------------------
>
> Key: JENA-1487
> URL: https://issues.apache.org/jira/browse/JENA-1487
> Project: Apache Jena
> Issue Type: Bug
> Components: ARQ
> Affects Versions: Jena 3.6.0
> Reporter: Claus Stadler
> Priority: Major
>
> Ordering an empty result set must not introduce additional bindings, but this
> happens with the following example (run on an arbitrary dataset - including
> an empty one):
> {code:bash}
> ./fuseki-server --file=test.ttl /foobar
> {code}
> The Json below is obtained from the Fuski bundle; but I noted this issue
> first using the ARQ API, where the result set contains a single
> BindingProjectNamed instance.
> {code:sql}
> SELECT ?s
> WHERE {
> ?s ?p ?o
> FILTER(false)
> }
> GROUP BY ?s
> ORDER BY DESC(COUNT(?o))
> {code}
> {code:json}
> {
> "head": {
> "vars": [ "s" ]
> } ,
> "results": {
> "bindings": [
> {
> # NOTE THIS EMPTY BINDING HERE!
> }
> ]
> }
> }
> {code}
> The result set is correct without the ORDER BY:
> {code:sql}
> SELECT ?s
> WHERE {
> ?s ?p ?o
> FILTER(false)
> }
> GROUP BY ?s
> {code}
> {code:json}
> {
> "head": {
> "vars": [ "s" ]
> } ,
> "results": {
> "bindings": [
> # CORRECT
> ]
> }
> }
> {code}
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