试图修改标识列'ID' [英] An attempt was made to modify the identity column ' ID'

问题描述

我的项目有问题。我的apache derby生成id，在表中它工作。但在应用程序中它不起作用。在德比中，我设置了id autoincrement（从1开始，增加1），但是我得到这个错误：

 >造成者：错误42Z23：试图修改身份
> 'ID'
  

。

我的实体：

  package com.springapp.mvc.models; 
 
 import javax.persistence。*; 
 
 @Entity 
 @Table（name =USERS，schema =KK，catalog =）
 public class UsersEntity {
 private int id; 
私人字符串名称; 
私人字符串密码; 
 
 @Id 
 @GeneratedValue（strategy = GenerationType.IDENTITY）
 @Column（name =ID）
 public int getId（）{
返回ID; 
} 
 
 public void setId（int id）{
 this.id = id; 
} 
 
 @Basic 
 @Column（name =NAME）
 public String getName（）{
 return name; 
} 
 
 public void setName（String name）{
 this.name = name; 
} 
 
 @Basic 
 @Column（name =PASSWORD）
 public String getPassword（）{
 return password; 
} 
 
 public void setPassword（String password）{
 this.password = password; 
} 
 
 @Override 
 public boolean equals（Object o）{
 if（this == o）return true; 
 if（o == null || getClass（）！= o.getClass（））return false; 
 
 UsersEntity that =（UsersEntity）o; 
 
 if（id！= that.id）return false; 
 if（name！= null？！name.equals（that.name）：that.name！= null）return false; 
 if（password！= null？！password.equals（that.password）：that.password！= null）return false; 
 
返回true; 
} 
 
 @Override 
 public int hashCode（）{
 int result = id; 
 result = 31 * result +（name！= null？name.hashCode（）：0）; 
 result = 31 * result +（password！= null？password.hashCode（）：0）; 
返回结果; 
 
 
 $ / code $ / pre 
 $ b $ h hibernate xml：
 
 
 <？xml version ='1.0'encoding ='utf-8'？> 
<！DOCTYPE hibernate-configuration PUBLIC 
 -  // Hibernate / Hibernate Configuration DTD // EN
http://www.hibernate.org/dtd/hibernate-configuration- 3.0.dtd> 
< hibernate-configuration> 
< session-factory> 
< property name =connection.url> jdbc：derby：// localhost：1527 / MyDB< / property> 
< property name =connection.driver_class> org.apache.derby.jdbc.ClientDriver< / property> 
 
 <！ -   -  SQL方言 - > 
< property name =dialect> org.hibernate.dialect.DerbyDialect< / property> 
<！ - < property name =hbm2ddl.auto>更新< / property> 
启用Hibernate的自动会话上下文管理 - > 
< property name =current_session_context_class>线程< / property> 
< mapping resource =mapping.xml/> 
< mapping class =com.springapp.mvc.models.AccountEntity/> 
< mapping class =com.springapp.mvc.models.BookEntity/> 
< mapping class =com.springapp.mvc.models.UsersEntity/> 
< / session-factory> 
< / hibernate-configuration> 
  
 mapping.xml 
 <？xml version ='1.0'encoding ='utf-8'？> 
<！DOCTYPE hibernate-mapping PUBLIC 
 -  // Hibernate / Hibernate映射DTD 3.0 // EN
http://www.hibernate.org/dtd/hibernate-mapping -3.0.dtd> 
< hibernate-mapping> 
 
< class name =com.springapp.mvc.models.AccountEntitytable =ACCOUNTschema =KK> 
< id name =idcolumn =ID/> 
< property name =namecolumn =NAME/> 
< property name =accountprefixcolumn =ACCOUNTPREFIX/> 
< property name =accountnumbercolumn =ACCOUNTNUMBER/> 
< property name =bankcodecolumn =BANKCODE/> 
< property name =useridcolumn =USERID/> 
< / class> 
< class name =com.springapp.mvc.models.BookEntitytable =BOOKschema =KK> 
< id name =idcolumn =ID/> 
< property name =titlecolumn =TITLE/> 
< property name =descriptioncolumn =DESCRIPTION/> 
< property name =useridcolumn =USERID/> 
< / class> 
< class name =com.springapp.mvc.models.UsersEntitytable =USERSschema =KK> 
< id name =idcolumn =ID/> 
< property name =namecolumn =NAME/> 
< property name =passwordcolumn =PASSWORD/> 
< / class> 
< / hibernate-mapping> 
  
谢谢 
 
解决方案如果您将ID表字段设置为自动增量，那么您不应该尝试插入一个ID，因为这是由德比自动生成的。
 
 
 
或使用Hibernate来生成你的id 
 
 $ p $ 
 @GeneratedValue（strategy = GenerationType.AUTO）
 private int ID; 
  

I have problem with my project. My apache derby generate id, in table it works. But in app it doesnt work. In derby I set id autoincrement (start with 1, increment by 1), but i get this error:

> Caused by: ERROR 42Z23 : An attempt was made to modify the identity
> column ' ID'

.

My entity:

package com.springapp.mvc.models;

import javax.persistence.*;

@Entity
@Table(name = "USERS", schema = "KK", catalog = "")
public class UsersEntity {
    private int id;
    private String name;
    private String password;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID")
    public int getId() {
        return id;
    }

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

    @Basic
    @Column(name = "NAME")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Basic
    @Column(name = "PASSWORD")
    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        UsersEntity that = (UsersEntity) o;

        if (id != that.id) return false;
        if (name != null ? !name.equals(that.name) : that.name != null) return false;
        if (password != null ? !password.equals(that.password) : that.password != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = id;
        result = 31 * result + (name != null ? name.hashCode() : 0);
        result = 31 * result + (password != null ? password.hashCode() : 0);
        return result;
    }
}

hibernate xml:

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="connection.url">jdbc:derby://localhost:1527/MyDB</property>
        <property name="connection.driver_class">org.apache.derby.jdbc.ClientDriver</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.DerbyDialect</property>
        <!-- <property name="hbm2ddl.auto">update</property>
Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>
        <mapping resource="mapping.xml"/>
        <mapping class="com.springapp.mvc.models.AccountEntity"/>
        <mapping class="com.springapp.mvc.models.BookEntity"/>
        <mapping class="com.springapp.mvc.models.UsersEntity"/>
    </session-factory>
</hibernate-configuration>

mapping.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>

    <class name="com.springapp.mvc.models.AccountEntity" table="ACCOUNT" schema="KK">
        <id name="id" column="ID"/>
        <property name="name" column="NAME"/>
        <property name="accountprefix" column="ACCOUNTPREFIX"/>
        <property name="accountnumber" column="ACCOUNTNUMBER"/>
        <property name="bankcode" column="BANKCODE"/>
        <property name="userid" column="USERID"/>
    </class>
    <class name="com.springapp.mvc.models.BookEntity" table="BOOK" schema="KK">
        <id name="id" column="ID"/>
        <property name="title" column="TITLE"/>
        <property name="description" column="DESCRIPTION"/>
        <property name="userid" column="USERID"/>
    </class>
    <class name="com.springapp.mvc.models.UsersEntity" table="USERS" schema="KK">
        <id name="id" column="ID"/>
        <property name="name" column="NAME"/>
        <property name="password" column="PASSWORD"/>
    </class>
</hibernate-mapping>

Thanks

解决方案

If you set the ID table field to auto-increment then you should not try to insert an id because this is auto generated by derby.

or use Hibernate to generate you id

@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;

这篇关于试图修改标识列'ID'的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！