I have created the field set as External Id and now I am changing the field to set as unique record identifier, I am not able to change, because Records exist already with duplicate values for that field.
So I want to query all the duplicate records. How do I perform a query to display the duplicate values for that particular field in test sandbox?
Then I will delete all the fields which contains duplicate External Ids, then I can change the field to Unique. Please anyone Guide me how to write a Query for Displaying the Duplicate Record Ids.