JSF :: Inserting Parent And Child Entities Into A Third Entity Using SelectOneMenu?

The company entity contains companyName, Sector and Segment columns. The mapping is 3 entities (Company, Sector, Segment) where Sector and Segment are used to create a company record. Sector has a OneToMany relationship with Segment and with Company. I put the Sector and Segment values into two select menus as use these to create a Sector and Segment reference for the Company table. I'm getting the following exception:

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot add or update a child row:
a foreign key constraint fails (`testdummy`.`company`, CONSTRAINT `FK_COMPANY_FK_COMPANY_SECTORID` FOREIGN KEY
(`FK_COMPANY_SECTORID`) REFERENCES `sectors` (`SECTORID`))
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

I'm thinking that the problem is that since the Segment entity is a child of Sector it must be entered through an instance of Sector. Because it's being entered as a separate value I'm getting this error. The problem is Segment is defined as a Set in the Sector entity and I can't figure out how to declare Segment as an instance using its parent entity (Sector).

My code is as follows, starting with the Sector entity:

@Entity
@Table(name = "SECTORSNEW")
public class SectorsNew {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int sectorId;
private String sectorName;
@OneToMany(cascade = CascadeType.PERSIST)

[code]....