Hello,

I have the following class structure:

@Entity
@Table(name="FOO")
@IdClass(FooPK.class)
public class Foo {
 private Long id;
 private String name;
 private String description;
 private List<FooBar> bars;

 @Id @Column(name="FOO_ID")
 public Long getId() {
 return id;
 }
 public void setId(Long id) {
 this.id = id;
 }

 @Id @Column(name="FOO_NAME")
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }

 public static class FooPK {
 private Long id;
 private String name;

 @Id @Column(name="FOO_ID")
 public Long getId() {
 return id;
 }
 public void setId(Long id) {
 this.id = id;
 }

 @Id @Column(name="FOO_NAME")
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 }
}

@Entity
@Table(name="BAR")
@IdClass(BarPK.class)
public class Bar {
 private Long id;
 private String name;
 private String description;

 @Id @Column(name="BAR_ID")
 public Long getId() {
 return id;
 }
 public void setId(Long id) {
 this.id = id;
 }

 @Id @Column(name="BAR_NAME")
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }

 public static class BarPK {
 private Long id;
 private String name;

 @Id @Column(name="BAR_ID")
 public Long getId() {
 return id;
 }
 public void setId(Long id) {
 this.id = id;
 }

 @Id @Column(name="BAR_NAME")
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 }
}

@Entity
@Table(name="FOO_BAR")
@IdClass(FooBarPK.class)
public class FooBar {
 private Foo foo;
 private Bar bar;
 private Date effectiveDate;
 private Date endDate;

 @Id @JoinColumn(name="FOO_ID")
 public Foo getFoo() {
 return foo;
 }
 @Id @JoinColumn(name="BAR_ID")
 public Bar getBar() {
 return bar;
 }
 @Id @Column(name="EFF_DATE")
 public Date getEffectiveDate() {
 return effectiveDate;
 }

 public static class FooBarPK {
 private Foo foo;
 private Bar bar;
 private Date effectiveDate;

 @Column(name="FOO_ID")
 public Foo getFoo() {
 return foo;
 }
 @Column(name="BAR_ID")
 public Bar getBar() {
 return bar;
 }
 @Column(name="EFF_DATE")
 public Date getEffectiveDate() {
 return effectiveDate;
 }
 }
}

The question I have relates to the FooBar class. The table behind it has FOO_ID and BAR_ID columns as part of the primary key. But I can't seem to figure out how to map these column values to appropriate Foo.id and Bar.id values. Any ideas on how I might be able to do this?

Thanks for your help.