I have an application which has 3 portals : Portal A, Portal B , and Portal C. A single user might want to use his/her same email account to sign up for different portals with different role setup and password. We are using Username and Password for signup and access.
In order to handle this situation, I have created 3 database connections :DB A, DB B and DB C under the same application. So that, when user signup on Portal A, I could create an account for him/her in DB A and vice versa. May I know would it be possible that the user_id (which suppose to be unique) be the same in DB A, DB B or DB C?