My first thoughts were on security. Can you confirm that the tables that you refer above have the same security settings?
I had the same thought initially, so I checked the security settings which are same.
I tried connecting to the same table (Invoice) through Qliksense and it works fine with Qliksense. However, with Qliksense I am unable to see orders header table which I am seeing with Tableau.
Strange things happening!!!!
Have you checked the logs on Tableau Desktop to see what queries are being fired to Oracle? Maybe it might be worth trying to run the same queries outside Tableau to see if you can separate out the issues.
Another approach would be to write a Custom SQL with just one column to see if that brings data for the invoice table on Tableau. If it does, I wonder if there's any unsupported data type that is causing an issue.
Let me know what you find..
I have already tried using Custom SQL but still I am not getting any records. Initially, I was joining order table and invoice table based on order number to get both order details and invoice details. That is when I realized there seems to be some issue with Invoice data as it was returning Null (using Custom SQL). I ran the same query in toad for oracle and it was running fine.
I just had a look at the logs and picked up the query , which is just a simple select query on invoice table and it is running fine outside tableau.
I guess it would be worth contacting Tableau support.