DB Session [...] invalid (Gupta SQL Base via JDBC)

Hi there,

I currently try to get a working connection to an Gupta SQLBase Database. Therefore i configured a new Database under preferences, linked the corresponding JAR-File and used the DB Connector node to connect. So far so good except for this error I found in the logs:

2020-11-04 13:03:26,266 : ERROR : KNIME-Worker-4-DB Connector 0:5 : : Node : DB Connector : 0:5 : Execute failed: DB Session 9dcbe856-915e-45d3-a119-c895cb5a8d6d is invalid. null
java.lang.IllegalStateException: DB Session 9dcbe856-915e-45d3-a119-c895cb5a8d6d is invalid. null
at org.knime.database.session.impl.DefaultDBSession.validate(DefaultDBSession.java:382)
at org.knime.database.node.connector.AbstractDBConnectorNodeModel.registerSession(AbstractDBConnectorNodeModel.java:389)
at org.knime.database.node.connector.AbstractDBConnectorNodeModel.execute(AbstractDBConnectorNodeModel.java:219)
at org.knime.core.node.NodeModel.executeModel(NodeModel.java:576)
at org.knime.core.node.Node.invokeFullyNodeModelExecute(Node.java:1236)
at org.knime.core.node.Node.execute(Node.java:1016)
at org.knime.core.node.workflow.NativeNodeContainer.performExecuteNode(NativeNodeContainer.java:558)
at org.knime.core.node.exec.LocalNodeExecutionJob.mainExecute(LocalNodeExecutionJob.java:95)
at org.knime.core.node.workflow.NodeExecutionJob.internalRun(NodeExecutionJob.java:201)
at org.knime.core.node.workflow.NodeExecutionJob.run(NodeExecutionJob.java:117)
at org.knime.core.util.ThreadUtils$RunnableWithContextImpl.runWithContext(ThreadUtils.java:334)
at org.knime.core.util.ThreadUtils$RunnableWithContext.run(ThreadUtils.java:210)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at org.knime.core.util.ThreadPool$MyFuture.run(ThreadPool.java:123)
at org.knime.core.util.ThreadPool$Worker.run(ThreadPool.java:246)
Caused by: java.lang.AbstractMethodError
at org.knime.database.connection.wrappers.AbstractConnectionWrapper.isValid(AbstractConnectionWrapper.java:431)
at org.knime.database.connection.wrappers.AbstractConnectionWrapper.isValid(AbstractConnectionWrapper.java:431)
at org.knime.database.connection.impl.managed.ManagedConnection.isValid(ManagedConnection.java:140)
at org.knime.database.connection.wrappers.AbstractConnectionWrapper.isValid(AbstractConnectionWrapper.java:431)
at org.knime.database.connection.wrappers.AbstractConnectionWrapper.isValid(AbstractConnectionWrapper.java:431)
at org.knime.database.connection.wrappers.AbstractConnectionWrapper.isValid(AbstractConnectionWrapper.java:431)
at org.knime.database.session.impl.DefaultDBSession.validate(DefaultDBSession.java:367)
ā€¦ 15 more

Can someone help to fix this invalid connection or have an idea why this occurs? If you need more details let me know!

Hi,
it seems as if the driver does not support the standard JDBC Connection.isValid() method. You can replace this by specifying a validation query e.g. SELECT 1 or SELECT * FROM SOMETABLE via the Validation query setting in the Advanced tab ob the DB Connector node.
If you get further problems with the generated SQL code you can tweak it by changing additional settings in the Advanced tab. To make the error searching easier you can also enable the logging of a statements that are send to the database via the JDBC logger option.
Bye
Tobias

2 Likes

Thank you very much Sir!

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