
CW.03153 (Customer) asked a question.
We are using Workday as a master and looking to have Workday push the username for the user. I am aware we need a custom expression to update this and I read that making this change will effect all existing Okta accounts.
Does anyone know what is directly affected with this change?

@CW.03153 (Customer) -- The answer to your question is going to be unique to your environment.
When you are importing data from Application -> Okta you can leverage Okta Expression Language (OEL) to transform the inputs however you want (within what OEL is capable of). The downstream effect of changing attributes is going to be dependent on your provisioning configuration of Okta --> Other Applications. If the attribute is being pushed Workday -> Okta -> Other App you would need to determine what impact on the "Other App" changing those attributes would cause.
@TimL.58332 (Workflows) yes, I want to use OEL to transform the inputs to what we want within Okta, but would like to determine what effects that will have with users in Okta and downstream apps.
In Workday > Provisioning > To Okta, if I change "Okta username format", what changes would that have?
The Okta Username Format is the Username that will be passed to Workday on SSO/Authentication. For example if you set the Okta Username Format to "Email" it will use the Email field in the Okta profile during authentication in the SAML assertion. This won't necessarily update the Username on the Workday side unless you have customization to do so.
If you need to push the username from Workday to Okta, you should review the profile mappings and sourcing for the username field in the profile editor.
Id recommend making username set as "create only" so that when you make this change it will only be for new users and not existing..if you want it to be create & update then you should make sure they are in sync manually before making the change. But also keep in mind, any downstream app reliant on the okta username for its mapping (IE: saml apps, etc) that could break it depending on how its setup. by default the SAML apps don't change their attribute like that.
It doesn't allow me to make username set as "Create only".
What I want to change is the "Okta username format" from Workday to Okta.