Export Google Analytics data (log of events)

Google Analytics doesn't provide you with any data that contains id

Its a part of Google Analytics Premium, you get a full table of all the info you want about fullVisitorId and visitId (sessionId)

Big Query Export Schema has a detailed info about the data you can have

There exists a way to do this without going for the premium service of Google Analytics

Solution : If you don't want the data to get aggregated add dimensions of your choice to segment the data. In this case user_id and event_id

Approach one

In Google Analytics Event Report is something you can use,

Event Category : send the user_id, generated by your JS code

Event Action : send the event_id, again generated by your JS code

Event Label : foo

Date this is a default dimension that is available in Google Analytics

Approach two

Custom Dimesnion : send the user_id, generated by your JS code

Event Category : send the event_id, generated by your JS code

Event Action : foo

Date this is a default dimension that is available in Google Analytics

There are benefits of using the second approach is that, once you set the custom dimension with a user_id, you can use it most of the reports other than the event report.

Data can be extracted from Google Analytics using Core Reporting API