關於使用休眠映射對象到數據庫

Question

大家好我是新的休眠。而我是衝浪的休眠相關主題的堆棧溢出，我發現這個

Need clarification about mapping objects to database, annotations, and one to many relationships

閱讀解決方案，我有點迷茫後開始建設的具體情況，瞭解多對一背後的實際機制，我在哪裏使用Oracle 11g數據庫。當我運行我的項目Hibernate是自動生成的表和FK的關係，而且在插入數據時就面臨這樣的問題（這是顯而易見的）

WARN: HHH000437: Attempting to save one or more entities that have a non-nullable association with an unsaved transient entity. The unsaved transient entity must be saved in an operation prior to saving these dependent entities. 
Unsaved transient entity: ([com.entity.Authorization#0]) 
Dependent entities: ([[com.entity.Job#1]]) 

WARN: HHH000437: Attempting to save one or more entities that have a non-nullable association with an unsaved transient entity. The unsaved transient entity must be saved in an operation prior to saving these dependent entities. 
    Unsaved transient entity: ([com.entity.JobFilteration#0]) 
    Dependent entities: ([[com.entity.Job#1]]) 
    Non-nullable association(s): ([com.entity.Job.jobfilteration]) 

我做了什麼是上述專題我的解決辦法剛纔提到，我張貼我的實體類（S）請幫我解決這個

類工作

@Entity 
@Table(name="JOB") 
public class Job implements Serializable { 
    @Id 
    @SequenceGenerator(name="person_seq", sequenceName="SEQ_PERSON",initialValue=1,allocationSize=1) 
    @GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="person_seq") 
    @Column(name="JOB_SERIAL") 
    private int id; 

    @Column(name="JOB_CATAGORY",nullable=false,length=200,unique=true) 
    private String catagory; 


    @ManyToOne(fetch=FetchType.LAZY) 
    @JoinColumn (name="JOB_AUTHID", nullable = false, updatable = false, insertable = false) 
    private Authorization authorization; 

    @ManyToOne(fetch=FetchType.LAZY) 
    @JoinColumn (name="JOB_JOBFILTERID", nullable = false, updatable = false, insertable = false) 
    private JobFilteration jobfilteration; 

類JobFilteration

@Entity 
@Table(name="JOB_FILTERATION") 
public class JobFilteration implements Serializable { 
    @Id 
    @SequenceGenerator(name="person_seq", sequenceName="SEQ_PERSON",initialValue=1,allocationSize=1) 
    @GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="person_seq") 
    @Column(name="FILTER_SERIAL") 
    private int id; 

    @Column(name="FILTERNAME",nullable=false,length=200) 
    private String filtername; 

類授權

@Entity 
@Table(name="AUTHORIZATION") 
public class Authorization implements Serializable { 
    @Id 
    @SequenceGenerator(name="person_seq", sequenceName="SEQ_PERSON",initialValue=1,allocationSize=1) 
    @GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="person_seq") 
    @Column(name="AUTH_ID") 
    private int id; 

    @Column(name="AUTHORISEDBY",nullable=false,length=200) 
    private String authorisedby; 

和用於插入我寫的方法public void insertToDB(Job job)的數據（我使用相同的序列爲三類，以節省時間），然後

JoBDao jobdao= new JoBDao(); 
Job job= null; 
Authorization auth = null; 
JobFilteration jfilter = null; 

try{ 
job= new Job(); 

auth = new Authorization(); 
    auth.setAuthorisedby("SOMEPERSON"); 

jfilter = new JobFilteration(); 
    jfilter.setFiltername("JEE"); 

job.setCatagory("PERMANENT"); 
job.setAuthorization(auth); 
job.setJobfilteration(jfilter); 


jobdao.addPersonandCard(job); 

我認爲發生異常是因爲數據在插入其他表之前插入到作業表中。請幫我找出我錯過了什麼？

Answer 1

最後，我已經想出了與作業類相關的問題，剩下的代碼（類）都可以。我在這裏粘貼正確的和修改工作實體

@Entity 
@Table(name="JOB") 
public class Job implements Serializable { 

    private static final long serialVersionUID = 1L; 

    @Id 
    @SequenceGenerator(name="person_seq", sequenceName="SEQ_PERSON",initialValue=1,allocationSize=1) 
    @GeneratedValue(strategy = GenerationType.SEQUENCE ,generator="person_seq") 
    @Column(name="JOB_SERIAL") 
    private int id; 

    @Column(name="JOB_CATAGORY",nullable=false,length=200,unique=true) 
    private String catagory; 


    /* The problem was inside this block */ 


    @ManyToOne(fetch=FetchType.LAZY,cascade = CascadeType.ALL) 
    @JoinColumn (name="JOB_AUTHID", nullable = false) 
    private Authorization authorization;         

    @ManyToOne(fetch=FetchType.LAZY,cascade = CascadeType.ALL) 
    @JoinColumn (name="JOB_JOBFILTERID", nullable = false) 
    private JobFilteration jobfilteration; 

Answer 2

看到您要存儲的對象。看起來你嘗試保存的對象對於那些不接受空值的字段爲空值。根據你的代碼，所有的數據列不能爲空。這意味着你不能對這些列中輸入空值

Answer 3

首先嚐試保存相關實體（在你的情況下授權），那麼儘量節省外實體（工作）

session.save(Authorization's object); 
session.save(Job's object) 

Answer 4

既然你有內部的兩個實體主要的，你需要先保存然後設置包含它們的主類中的實體。恐怕我真的不記得哪一個函數sesssion.save或session.saveOrUpdate返回bean，但是使用該方法，使用BeanUTils.copy方法並在主類中設置bean，一旦對所有實體都是這樣，saveOrUpdate主要的實體類。

希望這會有所幫助！