Object db relational database

[Envenomma]

Using Objectdb to develop this relational database. Can someone please help fix this code up. I am doing a relational database to display student grade results. New to this so i have gone wrong somewhere..\[code\]package Student;import java.io.Serializable;import java.sql.Date;import javax.persistence.*;@Entity public class students implements Serializable { private static final long serialVersionUID = 1L; @studentid @GeneratedValue private long id; } @embeddable public class Student { int studentid; String firstname; String surname; char gender; Date dob; String address1; String address2; String address3; char postcode; int phonenumber; int courseid; }@Entity public class courses implements Serializable { @EmbeddedId Course id; :}@Embeddable public class course { int courseid; string coursename; date coursestartdate; date courseenddate; }@entity public class moduledetails implements Serializable { private static final long serialVersionUID = 1L; @moduleId @GeneratedValue private long id;}@Embeddable public class module { int moduleid; String modulename; int courseid; int lectureid; }@entity public class lecturedetails implements Serializable { private static final long serialVersionUID = 1L; @lectureId @GeneratedValue private long id;}@Embeddable public class lecture { int lectureid; String lecturename; String lecturedepartment; }@entity public class resultdetails implements Serializable { private static final long serialVersionUID = 1L; @studentId @GeneratedValue private long id;@Embeddable public class result<Varchar> { int studentid; int courseid; int moduleid; Varchar modulename; char grade; }}\[/code\]Thanks!