How to resolve error: Splunk DB Connect Unable to get query metadata java.sql.SQLException

[parksy]

I'm using DB Connect app with MongoDB

Other inputs are very nice but only one input has a problem..

I did search _internal log and then I encountered below error

[dw-63 - POST /api/connections/LifeRecord/querymetadata] ERROR c.s.d.s.a.s.d.impl.DatabaseMetadataServiceImpl - Unable to get query metadata
java.sql.SQLException: Non-existing table referenced: exam
	at unity.parser.PTreeBuilderValidater.parseTableIdentifier(PTreeBuilderValidater.java:2551)
	at unity.parser.PTreeBuilderValidater.processTableRef(PTreeBuilderValidater.java:1203)
	at unity.parser.PTreeBuilderValidater.processTableReferences(PTreeBuilderValidater.java:1498)
	at unity.parser.PTreeBuilderValidater.ParseQuery(PTreeBuilderValidater.java:1113)
	at unity.parser.PTreeBuilderValidater.buildLQTree(PTreeBuilderValidater.java:967)
	at unity.parser.GlobalParser.parse(GlobalParser.java:101)
	at mongodb.jdbc.MongoPreparedStatement.parseQuery(MongoPreparedStatement.java:279)
	at mongodb.jdbc.MongoPreparedStatement.getMetaData(MongoPreparedStatement.java:249)
	at com.zaxxer.hikari.pool.HikariProxyPreparedStatement.getMetaData(HikariProxyPreparedStatement.java)
	at com.splunk.dbx.connector.connector.impl.JdbcConnectorImpl.getPrepareStatementMetaData(JdbcConnectorImpl.java:271)
	at com.splunk.dbx.connector.connector.impl.JdbcConnectorImpl.getQueryMetadata(JdbcConnectorImpl.java:124)
	at com.splunk.dbx.server.api.service.database.impl.DatabaseMetadataServiceImpl.getQueryMetadata(DatabaseMetadataServiceImpl.java:130)
	at com.splunk.dbx.server.api.resource.ConnectionResource.getQueryMetadata(ConnectionResource.java:166)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:124)
	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:167)
	at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:219)
	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:79)
	at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:469)
	at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:391)
	at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:80)
	at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:253)
	at org.glassfish.jersey.internal.Errors$1.call(Errors.java:248)
	at org.glassfish.jersey.internal.Errors$1.call(Errors.java:244)
	at org.glassfish.jersey.internal.Errors.process(Errors.java:292)
	at org.glassfish.jersey.internal.Errors.process(Errors.java:274)
	at org.glassfish.jersey.internal.Errors.process(Errors.java:244)
	at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:265)
	at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:232)
	at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:680)
	at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:394)
	at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:346)
	at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:366)
	at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:319)
	at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:205)
	at io.dropwizard.jetty.NonblockingServletHolder.handle(NonblockingServletHolder.java:50)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1651)
	at io.dropwizard.servlets.ThreadNameFilter.doFilter(ThreadNameFilter.java:35)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638)
	at io.dropwizard.jersey.filter.AllowedMethodsFilter.handle(AllowedMethodsFilter.java:47)
	at io.dropwizard.jersey.filter.AllowedMethodsFilter.doFilter(AllowedMethodsFilter.java:41)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638)
	at com.splunk.dbx.server.api.filter.ResponseHeaderFilter.doFilter(ResponseHeaderFilter.java:30)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1638)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:567)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1377)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:507)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1292)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at com.codahale.metrics.jetty9.InstrumentedHandler.handle(InstrumentedHandler.java:249)
	at io.dropwizard.jetty.RoutingHandler.handle(RoutingHandler.java:52)
	at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:717)
	at org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:54)
	at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:173)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.Server.handle(Server.java:501)
	at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383)
	at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
	at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:375)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938)
	at java.base/java.lang.Thread.run(Thread.java:829)

this error occured at restart the app

And then when arrived scheduled time, I encountered below error

[QuartzScheduler_Worker-10] ERROR org.easybatch.core.job.BatchJob - Unable to open record reader
com.splunk.dbx.server.exception.ConfMigrationFailException: Fail to migrate conf input, stanza name: <input name>.
	at com.splunk.dbx.server.dbinput.recordreader.DbInputRecordReader.migrateInputConfiguration(DbInputRecordReader.java:104)
	at com.splunk.dbx.server.dbinput.recordreader.DbInputRecordReader.open(DbInputRecordReader.java:50)
	at org.easybatch.core.job.BatchJob.openReader(BatchJob.java:140)
	at org.easybatch.core.job.BatchJob.call(BatchJob.java:97)
	at org.easybatch.extensions.quartz.Job.execute(Job.java:59)
	at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
	at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)

I need help.. What's the matter in this situation? Other Scheduled Input Jobs are very nice