Spring Data: Unique field in MongoDB document

Question

let's say I have the following database entity:

@Document(collection = "users")
public class User {

    @Id
    private String id;

    private String firstname;

    private String lastname;

    private String email; 

}

How can I enforce the field email to be unique? That means MongoDB should check if a user record with this email address already exists when the application tries to save the entity.

Regards, Steffen

Answer 1

Mongodb needs to create and index a field in order to know whether the field is unique or not.

@Indexed(unique=true)
private String email;