Publishing reports from power bi report builder without connecting to database

Hi Team

Few days back i have logged in into power bi report builder tool and setup the database. Logged in into datasource and setup the query. After successfull execution i got respective fields in left pane. I did drag and drop in table visual.

Later run the query and was successfull. I saved it.

Today when i opened the same file and followed all the steps except Logging into Datasource.( I have not logged in into Datasource).

Published the report to power bi service.

When i tried to open the published report in power bi service i am getting error like "cannot connect to underlying dataset, make sure credentials are correct".

 Kindly let me know what is the reason for getting this error.

Is there any step which i have missed or should be followed. 

Please help.