@JoinColumn problem

[adver11]

Hi, all
I have a problem about @JoinColumn.

Status.java

@Entity
public class Status implements Serializable {
 @Id
 private String Status_ID;

 private String Status_Msg;

 public String getStatus_ID() {
 return Status_ID;
 }

 public void setStatus_ID(String status_id) {
 Status_ID = status_id;
 }

 public String getStatus_Msg() {
 return Status_Msg;
 }

 public void setStatus_Msg(String status_msg) {
 Status_Msg = status_msg;
 }
}

Table Status:

Status_ID Status_Msg
----------- --------------
 O Open
 C Close
 F Fatal

Table Status have three lines data, unallowed insert other data.

Light.java

@Entity
public class Light implements Serializable {
 @Id
 private String Light_Name;

 @ManyToOne
 @JoinColumn(name = "Light_Status", referencedColumnName="Status_ID")
 private Status LightStatus;

 public String getLight_Name() {
 return Light_Name;
 }

 public void setLight_Name(String light_name) {
 Light_Name = light_name;
 }

 public Status getLightStatus() {
 return LightStatus;
 }

 public void setLightStatus(Status lightstatus) {
 LightStatus = lightstatus;
 }
}

Table Light

Light_Name Light_Status
-------------- --------------
light1 O
light2 O
light3 C
light4 F

Table Light Column Light_Status, auto create in @JoinColumn, not have setter/getter. How to do when i want to chang "light2" to Close(change Light_Status to "C").

another question:

Table Desk:

Desk_Zone Desk_ID
------------- -----------
 A 01
 B 09

Table ChkAllo

Desk_Code
-------------
 A01
 B09

How to create the OneToOne relationship about Desk.Desk_Zone + Desk.Desk_ID = ChkAllo.Desk_Code?