I am uploading case through dataloader . But while mapping the fields from CSV to salesforce fields "Created by" field is not showing on the time of mapping from data loader on the time of Insert the case in salesforce and this field is already visible from the salesforce.
Best Answer
The CreatedBy Field is a read-only field that cannot be updated via dataloader without "Set Audit Fields upon Record Creation" permissions. Previously you had to file a Case with Support to turn this permission on for a limited period of time when importing data. Without the permission enabled you won't see it mapped when using dataloader.
You no longer need to file a case with Salesforce to give a user "Set Audit Fields upon Record Creation" permissions to allow the user to Set audit fields, such as Created By, Last Modified By, and Created Date when you create a record (API only i.e Importing Tools) with Data Loader in order to make the Created Date writable.
See the following Knowledge Articles for more: 000171151, 000213290, and 000005202. You no longer need to file a support case with Salesforce as was necessary in the past.