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Create a custom field as an External Id filed field in each object that is going to use for data migration with data populated. Using the same field label for all the objects makes the setup easy.
It is a little difficult to populate the Populating unique data into the a new field can be a challenging task. To make simplify the process easy, you can create creating an Auto Number field first and after populating initial data into all existing rows , you can update can help. After that, the data type can be updated to Text, making it easier to populate unique data into the field.
Once After setting the External Id is set in all the relevant objects in the Prod Production Org, it is important to refresh the data to all the partial , and full sandboxes, and dev org to make it in Sync, as well as the Development Org, to ensure synchronization of the External Id field across all environments.
Setup in FlexDeploy
Create Salesforce package-based project or you can use an existing project if you already have one. Check our Salesforce Tutorial if you did not create a Salesforce project in FlexDeploy to start with.
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