function readOnly(count){ }
Starting November 20, the site will be set to read-only. On December 4, 2023,
forum discussions will move to the Trailblazer Community.
+ Start a Discussion
Mignu FMignu F 

Upsert from external data source to a custom object with Master-Detail

Hello,
I have a custom object called "contact_shows".  This custom object has master-detail relationship to the contact object; with the contact being the master and contact_shows being the detail.  I also have an external data source (SQL DB) that has the tables contact and contact_shows and there is a 1 to many relationship between contact and contact_shows on the SQL side; they are joined together via a customerid field.

We sync salesforce from an external SQL database on a nightly basis using informatica.  I have a sync job that succesfully updates/inserts (upsert) into the contact object.  The problem comes when I am trying to upsert into the contact_shows object.  The external data source doesn't know anything about the salesforce contactid which is what Salesforce uses when setting up a master detail relationship. 

How can i perform my nightly upsert in this scenario? Informatica rightfully complains that the required field 'Contact__c' is missing.  Any suggestions you have on this will be greatly appreciated.