The CData Cmdlets PowerShell Module for Smartsheet 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 Sheet_Customers.ContactName, Sheet_Orders.OrderDate FROM Sheet_Customers, Sheet_Orders WHERE Sheet_Customers.CustomerId=Sheet_Orders.CustomerId

Left Join

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

SELECT Sheet_Customers.ContactName, Sheet_Orders.OrderDate FROM Sheet_Customers LEFT OUTER JOIN Sheet_Orders ON Sheet_Customers.CustomerId=Orders.CustomerId