Hello, is there any support for ad-hoc queries in Drools or are there plans to introduce this feature ? Being part of the rule base queries are executed in the manner of prepared statements. To execute dynamic query patterns I currently create, add and remove a KB package containing the query. It would be great to have a dedicated/optimized utility method in Drools, that accepts a string pattern and returns QueryResults, like WorkingMemory#getQueryResults. There were similar requests earlier [1], [2], but they were not responded with regard to dynamic queries. [1] http://drools.46999.n3.nabble.com/Creating-ad-hoc-queries-td51522.html [2] http://drools.46999.n3.nabble.com/Inspecting-Working-Memory-td52382.html Best regards Jaro -- View this message in context: http://drools.46999.n3.nabble.com/Support-for-dynamic-ad-hoc-queries-in-D... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Hello Wolfgang, the suggested solution is an elegant syntactical shortcut to what I and other Drools users already do. Support for one-shot queries appears to be a meaningful extension to the WorkingMemory API, and the unavoidable effort of parsing and temporarily adding the query pattern to the production memory will become transparent to the user.

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> -----Original Message----- > From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users- > bounces(a)lists.jboss.org] On Behalf Of Wolfgang Laun > Sent: 27 June 2012 14:47 > To: Rules Users List > Subject: Re: [rules-users] Support for dynamic / ad-hoc queries in Drools > > On 27/06/2012, jpullmann <jaroslav.pullmann(a)fit.fraunhofer.de&gt; wrote: > > Hello Wolfgang, > > > > the suggested solution is an elegant syntactical shortcut to what I > > and other Drools users already do. Support for one-shot queries > > appears to be a meaningful extension to the WorkingMemory API, and > > the unavoidable > > > > effort of parsing and temporarily adding the query pattern to the > > production memory will become transparent to the user. > > There is still to be decided what to do when compilation fails - throw an > Exception or return null (with a factory method rather than a constructor). If there is any chance that null is a valid value to be returned (which I think there is?)

then it has to be an exception. Besides which it is nice to know why the compilation failed with a useful error message where possible.

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This would be a special case of a dynamic knowledge artifact (queries, rules, processes, etc..) being added to a knowledge base. The "low-level", runtime addition of an artifact is possible, so it would just need to be exposed in a more convenient way in the API.

Another (interesting) option would be to expose this feature at the KnowledgeAgent level, allowing dynamic, in-memory "(bytearray) resources". The added valye here is that the KA would ALSO be tracking the "resource" for modification and removal. Could you please open a Feature Request JIRA? We'll then discuss it and implement it. I have similar use cases and would be happy to sponsor it :) Davide p.s. as for the dynamic invocation a query you can do drools.getWorkingMemory().getQueryResults( ... ); in the RHS of a rule -- View this message in context: http://drools.46999.n3.nabble.com/Support-for-dynamic-ad-hoc-queries-in-D... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

... many thanks for your contributions! I have created a feature request: https://issues.jboss.org/browse/JBRULES-3561 Best regards Jaro -- View this message in context: http://drools.46999.n3.nabble.com/Support-for-dynamic-ad-hoc-queries-in-D... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

> Users, however, will expect to have the same situation for the "ad-hoc > query" as for all rules and queries built for the KnowledgBase from > which the called Session has been spawned Indeed, though there is a link from the session back to the parsed KB it is unaware of the builder and its configuration. The builder is a mandatory parameter for a method, that would correctly be scoped in the StatelessKnowledgeSession interface.

Best regards Jaro -- View this message in context: http://drools.46999.n3.nabble.com/Support-for-dynamic-ad-hoc-queries-in-D... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users