The CData Excel Add-In for Outreach 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 c.Id, o.Id, o.Name, o.Emails FROM Accounts c INNER JOIN Prospects o ON c.Id = o.AccountId

Left Join

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

 SELECT c.Id, o.Id, o.Name, o.Emails FROM Accounts c LEFT JOIN Prospects o ON c.Id = o.AccountId