“使用JPA和Spring引导在实体中映射实体的重复列”

  • Z时代
  • 2024-01-10
  • 分类：问答

我试图运行我的弹簧引导，ibatis，jpa应用程序。“使用JPA和Spring引导在实体中映射实体的重复列”

这是我在我的H2数据库中运行的sql脚本。

CREATE TABLE COMMITTEE(
    CODE NUMBER PRIMARY KEY, 
    NAME VARCHAR2(100), 
    P_CODE NUMBER, 
    CONSTRAINT P_CODE_FK FOREIGN KEY (P_CODE) REFERENCES COMMITTEE(CODE) 
); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(1, 'Parent 1', NULL); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(2, 'Parent 2', NULL); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(3, 'Parent 3', NULL); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(4, 'Child 1.1', 1); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(5, 'Child 1.2', 1); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(6, 'Child 1.3', 1); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(7, 'Child 3.1', 3); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(8, 'Child 3.2', 3); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(9, 'Child 3.3', 3); 
Insert into COMMITTEE(CODE, NAME, P_CODE) VALUES(10, 'Child 3.1.1', 7);

这里是我的实体：

package org.gso.committee.model; 
import java.io.Serializable; 
import java.util.ArrayList; 
import java.util.List; 
import javax.persistence.CascadeType; 
import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.FetchType; 
import javax.persistence.GeneratedValue; 
import javax.persistence.GenerationType; 
import javax.persistence.Id; 
import javax.persistence.JoinColumn; 
import javax.persistence.ManyToOne; 
import javax.persistence.OneToMany; 
import javax.persistence.Table; 
@Entity 
@Table(name = "committee") 
public class Committee implements Serializable { 
    private static final long serialVersionUID = 18787545L; 
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private long code; 
    private String name; 
    @Column(nullable = true) 
    private long p_code; 
    @ManyToOne() 
    @JoinColumn(name = "p_code") 
    private Committee parent; 
    @OneToMany(mappedBy = "parent") 
    private List<Committee> children = new ArrayList<>(0); 
    public Committee() { 
    } 
    public Committee(long code, String name, long p_code) { 
     this.code = code; 
     this.name = name; 
     this.p_code = p_code; 
    } 
    public long getCode() { 
     return code; 
    } 
    public void setCode(long code) { 
     this.code = code; 
    } 
    public String getName() { 
     return name; 
    } 
    public void setName(String name) { 
     this.name = name; 
    } 
    public long getP_code() { 
     return p_code; 
    } 
    public void setP_code(long p_code) { 
     this.p_code = p_code; 
    } 
    public Committee getParent() { 
     return parent; 
    } 
    public void setParent(Committee parent) { 
     this.parent = parent; 
    } 
    public List<Committee> getChildren() { 
     return children; 
    } 
    public void setChildren(List<Committee> children) { 
     this.children = children; 
    } 
    @Override 
    public String toString() { 
     return "Committee [code=" + code + ", name=" + name + ", p_code=" + p_code + "]"; 
    } 
}

的问题是，当我总是得到错误：

Caused by: org.hibernate.MappingException: Repeated column in mapping for entity: org.gso.committee.model.Committee column: p_code (should be mapped with insert="false" update="false")

回答：

的问题是，为什么你映射P_CODE作为一个单独的属性作为它已通过参考父级映射。

但是，如果你想要这个属性，你必须声明为只读

@Column(nullable = true, insertable = false, updateable = false) 
private long p_code;

它来设置父参考是非常重要的。做的是最好的方法是添加一些方便的方法是这样的：

public void addChild(Committee committee) { 
    committee.setParent(this); 
    children.add(committee); 
} 
public void removeChild(Committee committee) { 
    committee.setParent(null); 
    children.remove(committee); 
}

以上是 “使用JPA和Spring引导在实体中映射实体的重复列” 的全部内容， 来源链接： utcz.com/qa/266948.html

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