I have 2 tables - Call and Datum. Both have column call_id for association. I want to get all the call_ids from Call which do not also exist in Datum.
The SQL query, I think would be:
SELECT call_id FROM Call
LEFT OUTER JOIN Datum
ON Call.call_id = Datum.call_id
WHERE Datum.id = NULL
Let me know if this is wrong. But I need to know what it would look like in Ruby form. Please help!