I'm sorry for the post title. I wasn't sure how to word that... I have a query that is working fine:
SELECT
j.SubscriberKey,
j.JobID,
j.EventDate
from _Sent j
where
DATEPART(m, j.EventDate) = DATEPART(m, DATEADD(m, -1, GETDATE()))
AND DATEPART(yyyy, j.EventDate) = DATEPART(yyyy, DATEADD(m, -1, GETDATE()))
But I need to get another value c.Name in table Campaign_Salesforce, but in order to match I need to match values in yet another table Lead_Salesforce.
So Lead_Salesforce has a column Id which is the same as the SubscriberKey in my query above. Campaign_Salesforce has an Id column which matches the column Consumer_newsletter__c in Lead_Salesforce. Hopefully the picture below can help.