The CData Excel Add-In for Google Ads 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 CampaignPerformance.CampaignName, CampaignPerformance.Amount, ClickPerformance.Page FROM CampaignPerformance, ClickPerformance WHERE CampaignPerformance.CampaignId=ClickPerformance.CampaignId

Left Join

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

SELECT CampaignPerformance.CampaignName, CampaignPerformance.Amount, ClickPerformance.Page FROM CampaignPerformance LEFT OUTER JOIN ClickPerformance ON CampaignPerformance.CampaignId=ClickPerformance.CampaignId