4 Replies Latest reply: Apr 24, 2014 3:04 PM by Bob Hardaway RSS

    Custom Connectors with Direct Discovery

      Hi,

       

      I am interested in using my own custom connector with Direct Discovery.

      In order to test it out I am trying to use the QvEventLogConnectorElaborate custom connector of the SDK 2.0.

       

      The example given in the QvEventLogConnectorElaborate.qvw is a simple SELECT of all the fields provided by the connector to load them at LOAD time:

      CUSTOM CONNECT TO "Provider=QvEventLogConnectorElaborate.exe;Server=localhost;...";

      SQL SELECT Category,

          CategoryNumber,

          EntryType,

          Index,

          MachineName,

          Message,

          Source,

          TimeGenerated

      FROM ApplicationsEventLog;

       

       

      When I try to use it with Direct Discovery here is what I do:

      CUSTOM CONNECT TO "Provider=QvEventLogConnectorElaborate.exe;Server=localhost;...";

      DIRECT SELECT Category,

          CategoryNumber,

          EntryType,

          Index,

          MachineName,

          Message,

          Source,

          TimeGenerated

      FROM ApplicationsEventLog;

       

       

      The previous Direct query gives me a QVX_SYNTAX_ERROR error message from the QvxLibrary:

      QVX_SYNTAX_ERROR: Invalid query: SELECT CategoryID FROM ApplicationsEventLog GROUP BY CategoryID

      DIRECT SELECT CategoryID

      FROM ApplicationsEventLog

       

       

      Would anyone know what is the reason why I am getting this error message and if I could (if possible) use a customer connector with Direct Discovery?

      Am I missing something with implicit fields?

       

       

      Thanks,

        • Re: Custom Connectors with Direct Discovery
          Ralf Becher

          Hi,

           

          obviously the connector cannot handle aggregations. Direct Discovery is a feature which uses SQL aggregation queries only which consists of a GROUP BY clause and aggregation functions (count/min/max/sum/avg etc. for charts).

           

          Usually this functionality is only provided by a real database. I wonder if you're going to implement this in a connector..

           

          - Ralf

            • Re: Custom Connectors with Direct Discovery

              The reason I would like to use my own custom connector is that I don't the Qlikview to be soliciting my database whenever the user selection changes.

              Also, because of the size of the data I need to pull, I would like to be able to stream it during run time so that it is not loaded in-memory all at once.

               

              To address this problem I was thinking about creating my own datastore and use a custom connector to query it and stream it back to Qlikview.