By default during an update, Loader keeps existing data in your app and only adds values from the CSV file to empty data fields. The assumption is that a user wants to add new information to the app's data records or to populate in blanks. In this case the switch above the Mappings table is set to Off and the option Keep existing data in fields is selected.
Then, if you want to replace data in your app with values from your CSV file, turn the switch to the status Overwrite existing data in fields on.
To demonstrate how it works, consider the following:
1. You have the following Contact in your app:
2. And you have a CSV file that looks like that:
First Name, Last Name, Email
john, bridges, email@example.com
!!!Please note that last name was changed on purpose for illustration
3. Now you would like to add First Name to your existing record in your app
- During Mapping step use email to look for the records in your database
- Make sure the switch is Off and Keep existing data in fields is selected
- Run Update
- Now your records should look like this:
4. But what if you would like to change your Contact name as well
- In addition to all of the above, please turn the switch On to Overwrite existing data in fields on during the Mapping step. When your Update is complete, your record will look like this: