jpa one to many relationship unable giving exception

Question

I am trying to create populate Admin and AdminHealthPlan table.

The relationship between two is one to many (one admin can own many health plan).

The Admin class is defined as follows:

@Entity
@Table(name = "admin")
@NamedQueries(value = {
        @NamedQuery(name = "admin.getAdminById", query = "SELECT a "
            + "from  Admin a WHERE a.id=:id and deleted = 0"),
        @NamedQuery(name = "admin.getAdminByEmail", query = "SELECT a "
            + "from Admin a where a.email = :email and deleted = 0") })
public class Admin extends Persistent {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(name = "password")
    private String password;
    @Column(name = "email")
    private String email;
    @Column(name = "first_name")
    private String firstName;
    @Column(name = "last_name")
    private String lastName;
    @Column(name = "phone")
    private String phone;
    @OneToOne(mappedBy = "admin", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private AdminRole role;
    @OneToOne(mappedBy = "admin", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private AdminPasswordToken passwordToken;
    @OneToMany(mappedBy = "admin", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private Set<AdminHealthPlan> healthPlans;
    @Column(name = "deleted")
    private Boolean deleted = false;
    @Column(name = "security_question")
    private Integer securityQuestion;
    @Column(name = "security_answer")
    private String securityAnswer;

    public Admin() {}

    // Getters/setters
}

AdminHealthPlan class defined as follows.

@Entity
@Table(name = "admin_health_plan")
public class AdminHealthPlan implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(name = "health_plan")
    private String healthPlan;
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "admin_id", nullable = false)
    private Admin admin;
    @Column(name = "deleted")
    private Boolean deleted = false;

    public AdminHealthPlan() {}

    public AdminHealthPlan(String healthPlan) {
        this.healthPlan = healthPlan;
    }

    // Getters/setters
}

I create the admin object by retrieving the values from request and setting it into admin object and similarly for creating admin health plan set object and setting it in admin object and finally sending object to save to db.

it is giving exception as follows

May 21, 2012 6:49:16 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet appServlet threw exception
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Column 'admin_id' cannot be null
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    at com.mysql.jdbc.Util.getInstance(Util.java:381)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3558)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3490)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2109)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2648)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2077)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2362)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2280)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2265)
    at org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:105)
    at org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:105)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
    at org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
    at $Proxy70.executeUpdate(Unknown Source)

ws

For Creating Admin and AdminHealthPlan Object :

private Admin createAdminDummyObject() {
        Admin admin = new Admin();
        admin.setFirstName("Zuned");
        admin.setLastName("Ahmed");
        admin.setEmail("zuned@hcentive.com");
        admin.setPhone("123-1234454");
        admin.setHealthPlans(getHealthPlans(admin));
        return admin;
    }

    private Set<AdminHealthPlan> getHealthPlans(Admin admin) {
         Set<AdminHealthPlan> adminAHP = new HashSet<AdminHealthPlan>();
         AdminHealthPlan ahp = new AdminHealthPlan();
         ahp.setAdmin(admin);
         ahp.setHealthPlan("Plan1");
         adminAHP.add(ahp);
        return adminAHP;
    }

I used

getJpaTemplate().persist(t);

persist in db.

Can any body tell me what am I missing?

Answer 1

I use EclipseLink, so I'm not sure if it's done different in hibernate, but this is what I see wrong:

1- you didn't add the @Column annotation to the id attribute of the Admin entity.
2 - I always use GenerationType.IDENTITY for pks. 3 - In table AdminHealthPlan, the admin attribute has JoinColumn annotation but you didn't include referencedColumnName attribute. it should look like this: @JoinColumn(name = "admin_id", referencedColumnName = "admin_id")
4- for adding a new AdminHealthPlan to the Admin entity, I suggest that you do the following: create a method in Admin class called "addAdminHealthPlan":

public void addAdminHealthPlan(AdminHealthPlan ahp) {
    if(healthPlans == null) {
          healthPlans = new HashSet<AdminHealthPlan>();
    }
    ahp.setAdmin(this);
    healthPlans.add(ahp);
}

I don't know what is the method getJpaTemplate() and what is the object "t", but this would be the logic to persist the admin:

Admin admin = createAdminDummyObject();
AdminHealthPlan ahp = new AdminHealthPlan();
ahp.setAdmin(admin);
ahp.setHealthPlan("Plan1");
admin.addAdminHealthPlan(ahp);
entityManager.persist(admin);