The CData Power BI Connector for Kintone 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 Apps.Name, Comments.Text FROM Apps INNER JOIN Comments ON Apps.AppId = Comments.AppId WHERE Comments.Appid=5 AND Comments.RecordId=1

Left Join

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

SELECT Apps.Name, Comments.Text FROM Apps LEFT JOIN Comments ON Apps.AppId = Comments.AppId WHERE Comments.Appid=5 AND Comments.RecordId=1