The CData ADO.NET Provider for HubSpot supports standard SQL joins like the following examples.

Inner Join

An inner join selects only rows from both tables that match the join condition:

SELECT p.Name, a.FullName FROM BlogPosts p, BlogAuthors a WHERE p.AuthorUserId = a.Id

Left Join

A left join selects all rows in the FROM table and only matching rows in the JOIN table:

SELECT p.Name, a.FullName FROM BlogAuthors a LEFT JOIN BlogPosts p ON p.AuthorUserId = a.Id