What is the problem? Please be detailed.
Need to know how to connect to the mysql database in the ODK Aggregate installed in Google Cloud.
What ODK tool and version are you using? And on what device and operating system version?
What steps can we take to reproduce the problem?
What you have you tried to fix the problem?
Anything else we should know or have? If you have a test form or screenshots or logs, attach here.
I would like to connect to the mysql database odk_prod and do queries on the forms.
App Engine installs of ODK Aggregate are backed by Google's own data store. They are not backed my MySQL or PostgreSQL and thus you cannot do traditional SQL queries.
If you go to your Google Cloud Console you can write limited GQL queries against Aggregate's database structure if you'd like. You can also use the various Aggregate data transfer mechanisms.
If you need direct DB access, install Aggregate in a more self-contained manner (e.g., in a VM/VPS with Tomcat/PostgreSQL) on Google Compute Engine (or any other VPS infrastructure).