How to join two tables using dsQuery? Is it possible?
The dsQuery API function does not support table joins.
What you can do is to run a query on a Table and collect the ID Numbers.
Then you can pass those ID Numbers as an array to the table you want to join to via the dsQuery query parameter.
See the “IN” statement part - xml-rpc - Keap Developer Portal
Alternatively, you could setup a Saved Search which sometimes joins “internally” onto other tables, but it maybe limited to what fields you require.