Troubleshooting

Typical Problems and Their Solutions

GUI

"datasqill.app" cannot be opened

Both on macOS and Windows, the operating system may prevent datasqill from starting.

For macOS, start the application with the Control key pressed; then a prompt appears with an "Open" button that you simply click.

On Windows, switch in Explorer to the datasqill application, right-click and select "Properties". In the tab you will find at the bottom a "Security" section with the text "This file came from another computer. Access may have been blocked for security reasons." There you click the checkbox with "Allow" next to it.

No suitable driver found

This error message indicates a typo in the JDBC URL.

Verify whether the URL is correct. In the example, "h3" instead of "h2" can be seen. The URL should begin with "jdbc:h2:tcp/", followed by hostname, schema, etc.

If the error is not obvious, search for spaces or special characters in the URL.

UnknownHostException

This error message indicates an incorrect hostname in the JDBC URL.

With this error message, the computer on which the GUI is running is unable to resolve the hostname. In the example, the server "myserver" is not resolved.

Besides typos in the hostname, it could also be a problem with DNS resolution. Use "ping" to verify name resolution, for example:

ping myserver.softquadrat.de

If that works, the datasqill GUI should also be able to resolve it. If changes were made to DNS or the /etc/hosts file, a restart of the GUI is required before trying again.

TransformationsWithoutFolders

If orphaned worksheets (Sheets) exist in the database due to re-establishing an environment or deleting folders, the following SQL sequence must be executed in the H2 repository database:

DELETE FROM vv_sqts_action
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_object
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_layout
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_action_attribute
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_action_source
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_action_target
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

DELETE FROM vv_sqts_diagram_group
 WHERE sqts_diagram_group_id IN (
         SELECT sqts_diagram_folder_id
           FROM vv_sqts_diagram_group vsdg
          MINUS
          SELECT sqts_diagram_folder_id
            FROM vv_sqts_diagram_folder vsdf
       );

COMMIT;

H2

Locked Session in H2

• To identify a locked session, connect to the H2 database in an SQL editor and execute this SQL statement:

  SELECT * FROM INFORMATION_SCHEMA.sessions;
  

• In the results you see a session where CONTAINS_UNCOMMITTED is set:

• To terminate such a session, use this statement (use the ID from the previous step, in the screenshot ID = 525):

  CALL abort_session(ID);
  

Export H2 to SQL

Export data file as SQL:

java -cp ~/h2server/lib/h2-1.4.199_Softquadrat-P6.jar org.h2.tools.Script -url jdbc:h2:tcp://localhost:9092/datasqill -password <sa-password> -user sa -script datasqill.sql

Re-import into an empty database:

java -cp ~/h2server/lib/h2-1.4.199_Softquadrat-P6.jar org.h2.tools.RunScript -url jdbc:h2:tcp://localhost:9092/datasqill -password <sa-password> -user sa -script datasqill.sql