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    <p>If we take a concrete example would be as follows:</p> <p>Map for table1--> <code>COMPANIES</code>:</p> <pre><code> import java.io.Serializable; import java.util.List; import javax.persistence.Basic; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; @Entity @Table(name = "COMPANIES") public class Company implements Serializable { private static final long serialVersionUID = 1L; @Id @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "COMP_KEY") private String key; @Basic(optional = false) @NotNull @Size(min = 1, max = 100) @Column(name = "COMP_DESCRIPTION") private String description; @OneToMany(cascade = CascadeType.ALL, mappedBy = "company", fetch = FetchType.LAZY) private List&lt;Branch&gt; branches; //GETTERS, SETTERS... } </code></pre> <p>Map for table2--><code>BRANCHES</code></p> <pre><code> import java.io.Serializable; import java.util.List; import javax.persistence.Basic; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.EmbeddedId; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.OneToMany; import javax.persistence.Table; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; @Entity @Table(name = "BRANCHES") public class Branch implements Serializable { private static final long serialVersionUID = 1L; @EmbeddedId protected BranchPK branchPK; @Basic(optional = false) @NotNull @Size(min = 1, max = 100) @Column(name = "BRAN_DESCRIPTION") private String description; @JoinColumn(name = "BRAN_COMP_KEY", referencedColumnName = "COMP_KEY") @ManyToOne(optional = false, fetch = FetchType.LAZY) private Company company; @OneToMany(cascade = CascadeType.ALL, mappedBy = "branch", fetch = FetchType.LAZY) private List&lt;Employee&gt; staff; //GETTERS, SETTERS, ETC } import java.io.Serializable; import javax.persistence.Basic; import javax.persistence.Column; import javax.persistence.Embeddable; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; @Embeddable public class BranchPK implements Serializable { @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "BRAN_COMP_KEY") private String companyKey; @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "BRAN_KEY") private String brachKey; //GETTERS, SETTERS, ETC } </code></pre> <p>Map for table3--><code>STAFF</code></p> <pre><code> import java.io.Serializable; import javax.persistence.Basic; import javax.persistence.Column; import javax.persistence.EmbeddedId; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.JoinColumn; import javax.persistence.JoinColumns; import javax.persistence.ManyToOne; import javax.persistence.OneToOne; import javax.persistence.Table; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; @Entity @Table(name = "STAFF") public class Employee implements Serializable { private static final long serialVersionUID = 1L; @EmbeddedId protected EmployeePK employeePK; @Basic(optional = false) @NotNull @Size(min = 1, max = 15) @Column(name = "EMPL_NAME") private String name; @JoinColumns({ @JoinColumn(name = "EMPL_COMP_KEY", referencedColumnName = "BRAN_COMP_KEY", insertable = false, updatable = false), @JoinColumn(name = "EMPL_BRAN_KEY", referencedColumnName = "BRAN_KEY", insertable = false, updatable = false)}) @ManyToOne(optional = false, fetch = FetchType.EAGER) private Branch branch; @JoinColumns({ @JoinColumn(name = "EMPL_COMP_KEY", referencedColumnName = "BRAN_COMP_KEY", insertable = false, updatable = false), @JoinColumn(name = "EMPL_BRAN_SUPER", referencedColumnName = "BRAN_KEY", insertable = false, updatable = false)}) @OneToOne(optional = false) private Branch branchSupervice; @JoinColumns({ @JoinColumn(name = "EMPL_COMP_KEY", referencedColumnName = "BRAN_COMP_KEY", insertable = false, updatable = false), @JoinColumn(name = "EMPL_BRAN_VISIT", referencedColumnName = "BRAN_KEY", insertable = false, updatable = false)}) @OneToOne private Branch branchVisitor; //GETTERS, SETTERS, ETC } import java.io.Serializable; import javax.persistence.Basic; import javax.persistence.Column; import javax.persistence.Embeddable; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; @Embeddable public class EmployeePK implements Serializable { @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "EMPL_COMP_KEY") private String companyKey; @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "EMPL_BRAN_KEY") private String branchKey; @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "EMPL_KEY") private String employeeKey; //GETTERS, SETTERS, ETC } </code></pre> <p>I had a "home remedy" solution for this case. I created 2 extra fields to the primary key of each associated object.</p> <pre><code> @Entity @Table(name = "STAFF") public class Employee implements Serializable { private static final long serialVersionUID = 1L; //Besides the above mentioned code @Basic(optional = false) @NotNull @Size(min = 1, max = 4) @Column(name = "EMPL_BRAN_SUPER") private String keyBranchSupervice; @Size(max = 4) @Column(name = "EMPL_BRAN_VISIT") private String keyBranchVisitor; public void setBranchSupervice(Branch branchSupervice) { this.keyBranchSupervice = branchSupervice.branchPK.getBrachKey(); this.branchSupervice = branchSupervice; } } </code></pre> <p>And specified for each field in the same FK on the <code>setBranchSupervice</code> of the objects, I equaled values​​. With this I can add, edit, delete smoothly.</p> <p>But I still have the doubt as it should be (good practice).</p>
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