java - hibernate java中哪个生成的类用于字符串类型主键？或任何需要字符串类型的生成器类

Question

Hibernate Java 中哪个生成的类用于字符串类型主键？或者是否需要 String 类型的生成器类？

使用更新时出现错误

org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

这是我的实体类 Book.java

import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
//import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import org.springframework.format.annotation.DateTimeFormat;
@Entity
@Table(name="book1")
public class Book {

    @Id
    @Column(unique=true,length=20)
    private String ACC_NO;
    private String CALL_NO;
    private String AUTHOR;
    private String TITLE;
    private String IMPRINT;
    private String YEAR;
    private String EDITION;
    private String SUBJECT;
    private String SERIES;
    private String PAGES;
    @DateTimeFormat(pattern="mm/dd/yyyy")
    private Date DATE_RELEASE;
    private String BOOK_STATUS;
    private Byte RESER_STATUS;
    public String getACC_NO() {
        return ACC_NO;
    }
    public void setACC_NO(String aCC_NO) {
        ACC_NO = aCC_NO;
    }
    public String getCALL_NO() {
        return CALL_NO;
    }
    public void setCALL_NO(String cALL_NO) {
        CALL_NO = cALL_NO;
    }
    public String getAUTHOR() {
        return AUTHOR;
    }
    public void setAUTHOR(String aUTHOR) {
        AUTHOR = aUTHOR;
    }
    public String getTITLE() {
        return TITLE;
    }
    public void setTITLE(String tITLE) {
        TITLE = tITLE;
    }
    public String getIMPRINT() {
        return IMPRINT;
    }
    public void setIMPRINT(String iMPRINT) {
        IMPRINT = iMPRINT;
    }
    public String getYEAR() {
        return YEAR;
    }
    public void setYEAR(String yEAR) {
        YEAR = yEAR;
    }
    public String getEDITION() {
        return EDITION;
    }
    public void setEDITION(String eDITION) {
        EDITION = eDITION;
    }
    public String getSUBJECT() {
        return SUBJECT;
    }
    public void setSUBJECT(String sUBJECT) {
        SUBJECT = sUBJECT;
    }
    public String getSERIES() {
        return SERIES;
    }
    public void setSERIES(String sERIES) {
        SERIES = sERIES;
    }
    public String getPAGES() {
        return PAGES;
    }
    public void setPAGES(String pAGES) {
        PAGES = pAGES;
    }
    public String getBOOK_STATUS() {
        return BOOK_STATUS;
    }
    public void setBOOK_STATUS(String bOOK_STATUS) {
        BOOK_STATUS = bOOK_STATUS;
    }
    public Byte getRESER_STATUS() {
        return RESER_STATUS;
    }
    public void setRESER_STATUS(Byte rESER_STATUS) {
        RESER_STATUS = rESER_STATUS;
    }
    public Date getDATE_RELEASE() {
        return DATE_RELEASE;
    }
    public void setDATE_RELEASE(Date dATE_RELEASE) {
        DATE_RELEASE = dATE_RELEASE;
    }
}


**Update command in BookDAOImpl.java is below use for both save and Update**

@Override
    @Transactional
    public void saveBook(Book Book) {
        sessionFactory.getCurrentSession().saveOrUpdate(Book);
    }

Answer 1

对于基于字符串的主键，您有两种选择:

• 使用 UUID 生成器之一将生成的 UUID 存储为字符串。
• 编写您自己的基于字符串的自定义生成器。

Hibernate 中的其他生成器主要处理从基于表的特定 IDENTITY 或 AUTO_INCRMENT 列或 SEQUENCE 获取的数值由数据库的序列支持或自定义 hibernate_sequences 表提供。