The CData JDBC Driver for Bullhorn CRM supports standard SQL joins like the following examples.
An inner join selects only rows from both tables that match the join condition:
SELECT c.CandidateName, o.Certification, o.GraduationDate, o.Comments FROM Candidate c INNER JOIN CandidateEducation o ON c.Id = o.CandidateId
A left join selects all rows in the FROM table and only matching rows in the JOIN table:
SELECT c.Subject, o.AttendeeId FROM Appointment c LEFT JOIN AppointmentAttendee o ON c.Id = o.AppointmentId