Do I need to Set Foreign key value in JPA? - jpa-2.0

Question

I have two table:
CREATE TABLE [LeTYPE](
[LeNAME] [varchar](100) NOT NULL,
[Le_DESC] [varchar](500) NULL,
[LeFOR] [varchar](50) NOT NULL,
CONSTRAINT [PK_LeTYPE] PRIMARY KEY CLUSTERED
(
[LeNAME] ASC
)
)
CREATE TABLE [Le](
[SN] [int] IDENTITY(1,1) NOT NULL,
[LeNAME_FK] [varchar](100) NOT NULL,
[Le_SN] [int] NULL,
[LOWERRANGE] [float] NOT NULL,
[UPPERRANGE] [float] NOT NULL,
[Le_DESC] [varchar](500) NULL,
[COLOR] [varchar](45) NULL,
CONSTRAINT [Le_pk] PRIMARY KEY CLUSTERED
(
[SN] ASC
))
GO
ALTER TABLE [Le] WITH CHECK ADD CONSTRAINT [FK_Le_LeTYPE] FOREIGN KEY([LeNAME_FK])
REFERENCES [LeTYPE] ([LeNAME])
ON UPDATE CASCADE
ON DELETE CASCADE
GO
ALTER TABLE [Le] CHECK CONSTRAINT [FK_Le_LeTYPE]
GO
One tuple in LETYPE will have many LE.
JPA Entity generated by netbeans:
public class Letype implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 100)
#Column(nullable = false, length = 100)
private String Lename;
#Size(max = 500)
#Column(name = "Le_DESC", length = 500)
private String LeDesc;
#Basic(optional = false)
#NotNull
#Size(min = 1, max = 50)
#Column(nullable = false, length = 50)
private String Lefor;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "LenameFk", fetch = FetchType.LAZY)
private List<Le> LeList;
}
public class Le implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#NotNull
#Column(nullable = false)
private Integer sn;
#Column(name = "Le_SN")
private Integer LeSn;
#Basic(optional = false)
#NotNull
#Column(nullable = false)
private double lowerrange;
#Basic(optional = false)
#NotNull
#Column(nullable = false)
private double upperrange;
#Size(max = 500)
#Column(name = "Le_DESC", length = 500)
private String LeDesc;
#Size(max = 45)
#Column(length = 45)
private String color;
#JoinColumn(name = "LeNAME_FK", referencedColumnName = "LeNAME", nullable = false)
#ManyToOne(optional = false, fetch = FetchType.LAZY)
private Letype LenameFk;
}
Now, What I wanted was if I add a LETYPE from JSF view I would like to add multiple LE also at the same time.
LETYPE
-LE1
-LE2
-LE3
Do I need to set LenameFk manually in Le entity since I am getting
*Cannot insert the value NULL into column 'LENAME_FK'*? Why won't it automatically take it from Le enityt?

Answer 1

Note this snippet of code:
public class Le implements Serializable {
...
#ManyToOne(optional = false, fetch = FetchType.LAZY)
private Letype LenameFk;
...
}
optional = false means any instance of this entity must participate the relation, so, the foreign key field can not be null.

Answer 2

Your right, You need to set LenameFk manually in Le entity.
In General , for Bi-directional one-to-many two way relation , Accessor method should like below and assume entities are Customer and Order and one-to-many relation b/w them.
Customer.java
public Collection<Order> getOrders() {
return Collections.unmodifiableCollection(orders);
}
public void addToOrders(Order value) {
if (!orders.contains(value)) {
orders.add(value);
value.setCustomer(this);
}
}
public void removeFromOrders(Order value) {
if (orders.remove(value)) {
value.setCustomer(null);
}
}
Order.java
public void setCustomer(Customer value) {
if (this.customer != value) {
if (this.customer != null) {
this.customer.removeFromOrders(this);
}
this.customer = value;
if (value != null) {
value.addToOrders(this);
}
}
}
public Customer getCustomer() {
return customer;
}