There could be 2 scenarios for this problem;
1. Not getting data in the preview tab of the dataset in your local machine
Solution: if you get table metadata in the dataset, you have to write a query in the query editor in order to get the table data.
2. Not getting table metadata from the data source connection
This might be because user you have used to connect with the database does not have the right to read metadata.
Workaround: Try to connect with the database using the root user or admin user and check if you are getting tables metadata or not. if you are getting metadata using the root or admin user then check the non-admin user's access settings.