I design an ER-model of IS. How to link three IDs of different user roles in one USERS entity attribute?

Question

SQL

I am designing an ER model of an information system, there are entities by roles: Admins, Customers, Performers - each has its own identifiers. How to connect them into one USERS entity, where there are also attributes: Password, Reg_date, Acc_type - password, registration date, account type? Add an id_user attribute at the end of each table entity, and is it already a key in USERS? More ways?

Answer 1

I can be wrong, because. I don’t know the details of the TOR, but the term “Role” suggests the entity “Role” which has the attribute “Role” with possible values ​​“Admins”, “Customers”, “Contractors”

Answer 2

If the relationship is 1 to 1, then you can link the group ID with the field to the user, if there can be more than 1 groups, then through a separate link table where there will be user 1 group 1 user 1 group 2

Answer 3

Why make an entity for each group? It's easier to add a role field.