Hi Claude,
1/ Suggestion
if there is no addVar then the query defaults to SELECT *.
2/ Suggestion
Strip any trailing ":" from the prefix name so
.addPrefix(":", "http://example/";)
works.
3/ I tried:
SelectBuilder sb = new SelectBuilder() ;
sb.addVar("*")
.addPrefix("", "http://example/";)
.addWhere(":S", "?p", "?o") ;
Query query = sb.build() ;
System.out.println(query) ;
and got:
-----------------
Exception in thread "main" java.lang.IllegalArgumentException: Predicate
(?p) must be a URI , variable, or a wildcard.
Is a prefix missing? Prefix must be defined before use.
org.apache.jena.arq.querybuilder.handlers.WhereHandler.testTriple(WhereHandler.java:124)
org.apache.jena.arq.querybuilder.handlers.WhereHandler.addWhere(WhereHandler.java:129)
org.apache.jena.arq.querybuilder.SelectBuilder.addWhere(SelectBuilder.java:194)
org.apache.jena.arq.querybuilder.SelectBuilder.addWhere(SelectBuilder.java:206)
dev.QBuild.main(QBuild.java:34)
-----------------
while
("?s", "?p", "?o") works.
Andy
On 19/09/14 22:51, Claude Warren wrote:
I have added license and javadoc comments as well as a readme.md In
addition the above mentioned bug is now fixed and addVar( "*" ) works as
expected.
On Fri, Sep 19, 2014 at 1:24 PM, Claude Warren <[email protected]> wrote:
I started looking at it this AM. I think the proper solution is to accept
"*" as a var in the selecthandler. I will look at it over the weekend and
will add documentation (javadoc at least)
On Fri, Sep 19, 2014 at 10:14 AM, Andy Seaborne <[email protected]> wrote:
On 19/09/14 05:18, Bruno P. Kinoshita wrote:
Hello Claude,
I didn't understand what QueryBuilder was supposed to do at first, or
how to use it. Luckily there are tests in the project, kudos for writing
those, very helpful. I liked the idea, and for users familiar with Java
Jooq, PHP and Ruby ActiveRecord that's definitely an intuitive API.
In order to test it, I first created some dummy data.
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX : <http://example.org/>
INSERT DATA
{
:bruno foaf:name "Bruno" .
:jorge foaf:name "Jorge" .
:bruno :brotherOf :jorge
}
Then I retrieved the data with a simple SELECT.
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX : <http://example.org/>
SELECT *
{
?a ?b ?c
}
---------------------------------
| a | b | c |
=================================
| :bruno | foaf:name | "Bruno" |
| :bruno | :brotherOf | :jorge |
| :jorge | foaf:name | "Jorge" |
---------------------------------
I tried to recreate the same query with QueryBuilder, but alas it didn't
work. I have probably made something really stupid [1]. My output is always:
PREFIX : <http://example.org/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
WHERE
{ ?a ?b ?c . }
I just wanted to validate that I could recreate the same query with
QueryBuilder. But I couldn't figure how that works. Looking at
WhereClauseTest, I thought that addVar("*") would result in "SELECT *". The
prefixes is not keeping the order it was added, thus that's probably not an
issue.
The SelectBuilder throws ParseException, which extends Exception. I
think **if** the Query Builder is supposed to be used by programmers for
writing their Web applications or similar, then perhaps it could extend a
RuntimeException?
Just my 0.002 cents
Thanks
Bruno
[1] https://gist.github.com/kinow/b50a5d3b875f2155b7bb
Ditto.
(I have just pushed a fix to Wherehandler.testTriple.)
Andy
--
I like: Like Like - The likeliest place on the web
<http://like-like.xenei.com>
LinkedIn: http://www.linkedin.com/in/claudewarren
