How to display certain elements from a table?

Question

Java

Need your help, I'm not from the Java world. So to say help my colleague.
The task is this:
There is a database of accounts (Google). You need to make a function that will check the account for the presence of the history element (they say the account has activity or not). It is assumed that in the child history object there will be an element of emal (who made the last commit, so to speak). Well, in the end it will display those accounts that have a history object.
Supporting information : AdWords API