Data Loader Org to Org. Connecting mass children to parent Accounts?

Question

Data Loader > Org to Org > How to connect mass children to their parent Accounts?

Ok so I Inserted the parents. 1000+

I have a field where the old Account ID's are stored on the new Org.

Now I have 300+ children that I need to insert.

The Children need the Parents 18 Digit ID. (I know this part)

Without going through them 1 by 1, and matching the child's Parent ID to the New Parent ID, how do I match them up before inserting then children?

Does anybody have a video on this? I've dug for hours on the internet and haven't found anything useful.

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Troubleshooting Images:

Answer 1

I have a field where the old Account ID's are stored on the new Org.

This is wise. Make sure that field is marked as an External Id.

Without going through them 1 by 1, and matching the child's Parent ID to the New Parent ID, how do I match them up before inserting then children?

If you hadn't stored the old parent Id on the new Accounts, you would need to use VLOOKUP() or INDEX()/MATCH() constructs in your spreadsheets to map the old Account Ids to the new Account Ids. But you did, and if you also mark that field as External Id, you get to use a much simpler approach.

In Data Loader, rather than performing an insert of your Contacts, perform an upsert. As you click through the steps to define your upsert operation, you will be offered the chance to map the relationship fields on your Contact objects to External Ids on the parent.

What you want to do is map the AccountId field on your Contacts to the External Id field holding the old Account Id. Salesforce will then do the mapping for you to associate the Contact with the new parent Account via that shared identifier.