使用@ManyToMany JPA注释时不需要的唯一约束

Question

我在我的项目中使用spring boot/spring data jpa。spring发布后，下面的实体将在oracle中创建表。jpa。冬眠ddl auto设置为更新。

@Entity
@Table(name = "SCENARIO")
public class Scenario {

    private Integer worksetId;
    private Integer ruleSetId;
    private Set<Rule> rules;

    @Id
    public Integer getWorksetId() {
        return worksetId;
    }

    public void setWorksetId(Integer worksetId) {
        this.worksetId = worksetId;
    }

    @Column(name = "RULE_SET_ID")
    public Integer getRuleSetId() {
        return ruleSetId;
    }

    public void setRuleSetId(Integer ruleSetId) {
        this.ruleSetId = ruleSetId;
    }

    @ManyToMany
    @JoinTable(name = "RULE_SET", joinColumns = @JoinColumn(name = "WORKSET_ID", referencedColumnName = "RULE_SET_ID"), inverseJoinColumns = @JoinColumn(name = "RULE_ID", referencedColumnName = "ID"))
    public Set<Rule> getRules() {
        return rules;
    }

    public void setRules(Set<Rule> rules) {
        this.rules = rules;
    }

}

@Entity
@Table(name = "RULE")
public class Rule {
    private Integer id;
    private String description;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

}

我期待的是非常简单的场景/规则表将被创建，以及一个名为RULE_SET的映射表。一切都很顺利，只是在表场景中创建了一个不需要的对RULE_SET_ID的唯一约束，但显然相同的RULE_SET_ID应该能够被多个场景共享。谁能帮忙吗？非常感谢！！

顺便说一句，我正在使用带有Hibernate5.0.9的Spring-boot 1.4.0

Answer 1

显然，如果您使用了referencedColumnName=“RULE_SET_ID”，RULE_SET_ID，则应该是唯一的。

您可以为Scenario使用代理键

@Entity
@Table(name = "SCENARIO")
public class Scenario {

    @Id
    @GeneratedValue
    private Integer id;

}

并使用@manytomy映射

@ManyToMany
@JoinTable(name = "RULE_SET", joinColumns = @JoinColumn(name = "WORKSET_ID"), 
    inverseJoinColumns = @JoinColumn(name = "RULE_ID"))
public Set<Rule> getRules() {
    return rules;
}

使现代化

我想使用规则集实体来表示一组规则（使用联接表进行映射）：

@Entity
class RuleSet {

  @OneToMany
  private List<Rule> rules = new ArrayList<Rule>();

}