JPA - Repeated column in mapping for entity #OneToOne - jpa

Question

I have two simple tables: Users and User_Roles.
In both tables i have a field email and i want load User_Roles from UserEntity, the query should be:
SELECT *
FROM Users u, User_Roles ur
WHERE u.email = ur.email;
When i try to "link" the email field i get the error "Repeated column in mapping for entity: UserEntity column: email".
I've tried to add any kind of combination (mappedBy, refColumn etc) but the error is even the same...
User
#Entity
#Table(name = "users")
public class UserEntity implements Serializable {
private static final long serialVersionUID = 1L;
private long id;
private String email;
private UserRolesEntity roles;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
#Basic
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
#OneToOne
#JoinColumn(name = "email")
public UserRolesEntity getRoles() {
return roles;
}
public void setRoles(UserRolesEntity roles) {
this.roles = roles;
}
}
User_Roles
#Entity
#Table(name = "user_roles")
public class UserRolesEntity {
private long id;
private String email;
private String role;
#Id
#Column(name = "user_role_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
#Basic
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
#Basic
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
}

Answer 1

If you want to link the User_Roles and User, you should keep the User's primary key in User_Roles. So you would better modify your User_Roles table like this:
long user_role_id
long user
String role
Then your User_Roles class would be:
#Entity
#Table(name = "user_roles")
public class UserRolesEntity {
private long id;
private User user;
private String role;
#Id
#Column(name = "user_role_id")
#GeneratedValue(strategy = GenerationType.IDENTITY)
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
#OneToOne
public User getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
#Basic
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
}
If you want get the user email from user_role, you can do like this: userRole.getUser().getEmail()
And then the User class would be:
#Entity
#Table(name = "users")
public class UserEntity implements Serializable {
private static final long serialVersionUID = 1L;
private long id;
private String email;
private UserRolesEntity roles;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
#Basic
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
#OneToOne(mappedBy="user")
public UserRolesEntity getRoles() {
return roles;
}
public void setRoles(UserRolesEntity roles) {
this.roles = roles;
}
}