How Do You Troubleshoot the GCP BigQuery Error ‘Table name “foobar” missing dataset while no default dataset is set in the request’?

Problem scenario
You run a BigQuery query. But you get a pop-up message that says 'Table name "mockdata" missing dataset while no default dataset is set in the request.'

What should you do?

Solution
Did you specify a dataset (or database name) before foobar?

For example, if your dataset is called "cool", your BigQuery query should refer to "foobar" as "cool.foobar". Here is an example of a working query:

select * from cool.foobar;