JPA Eclipselink错误："字段'Target_id'没有默认值"

Question

我会尽量短一点

异常在线程"main"javax.persistence.持久性异常：异常[Eclipse链接-4002]（Eclipse持久性服务-2.5.2. v20140319-9ad6abd）：org.eclipse.persistence.exceptions.数据库异常内部异常：java.sql.SQLExc0019：字段'Target_id'没有默认值错误代码： 1364调用：插入目标（32_bit_arch，IP，名称，Operating_system）值 (?, ?, ?, ?)绑定

我已经搜索了SO和Google，但即使我发现类似的情况（例如，这一个），解决方案似乎也不起作用（使用@JoinColumn（nullable=false）或appplying@OneToMany（orphanRemoving=true）删除非空约束），等等。有关资料如下:

1.MySQL表创建脚本：

-- -----------------------------------------------------
-- Table `fault_injector`.`Target`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `fault_injector`.`Target` ;

CREATE TABLE IF NOT EXISTS `fault_injector`.`Target` (
  `Target_id` INT NOT NULL AUTO_INCREMENT,
  `Name` VARCHAR(30) NOT NULL,
  `32_bit_arch` TINYINT(1) NOT NULL,
  `IP` VARCHAR(15) NOT NULL,
  `Operating_system` VARCHAR(30) NOT NULL,
  PRIMARY KEY (`Target_id`),
  UNIQUE INDEX `idTarget_UNIQUE` (`Target_id` ASC),
  UNIQUE INDEX `IP_UNIQUE` (`IP` ASC))
ENGINE = InnoDB;

-- -----------------------------------------------------
-- Table `fault_injector`.`Experiment`
-- -----------------------------------------------------
DROP TABLE IF EXISTS `fault_injector`.`Experiment` ;

CREATE TABLE IF NOT EXISTS `fault_injector`.`Experiment` (
  `Exp_id` INT NOT NULL AUTO_INCREMENT,
  `Creator_id` INT NOT NULL,
  `Target_id` INT NOT NULL,
  `Name` VARCHAR(30) NOT NULL,
  `Creation_date` TIMESTAMP NOT NULL,
  `Injection_date` TIMESTAMP NULL,
  `Description` VARCHAR(300) NOT NULL,
  PRIMARY KEY (`Exp_id`),
  UNIQUE INDEX `Experiment_id_UNIQUE` (`Exp_id` ASC),
  INDEX `Target_id_idx` (`Target_id` ASC),
  INDEX `User_id_idx` (`Creator_id` ASC),
  CONSTRAINT `Experiment_User_id_fk`
    FOREIGN KEY (`Creator_id`)
    REFERENCES `fault_injector`.`User` (`User_id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `Experiment_Target_id_fk`
    FOREIGN KEY (`Target_id`)
    REFERENCES `fault_injector`.`Target` (`Target_id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

2.目标实体：

@Entity
@NamedQuery(name="Target.findAll", query="SELECT t FROM Target t")
public class Target implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="Target_id")
    private int target_id;

    [...]

    //bi-directional many-to-one association to Experiment
    @OneToMany(mappedBy="target")
    private List<Experiment> experiments;

    [...]

    public List<Experiment> getExperiments()
    {
        if(this.experiments==null)
            this.experiments = new ArrayList<Experiment>();

        return this.experiments;
    }

    public Experiment addExperiment(Experiment experiment) {
        getExperiments().add(experiment);
        experiment.setTarget(this);

        return experiment;
    }

3.实验单位：

@Entity
@NamedQuery(name="Experiment.findAll", query="SELECT e FROM Experiment    e")
public class Experiment implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)
    @Column(name="Exp_id")
    private int exp_id;

    [...]

    //bi-directional many-to-one association to Target
    @ManyToOne(cascade = CascadeType.PERSIST)
    @JoinColumn(name="Target_id")
    private Target target;

    [...]

    public void setTarget(Target target) {
        this.target = target;
    }

4.代码

尽管编译器说错误发生在实体管理器调用flush（em.flush（））时 ），我知道另一行与错误相关，因为如果我对它进行注释，错误就会消失：target。附加实验（实验） （请注意，target和Experience都是同名实体的实例-如果需要，我可以发布更多代码，但现在我试图让问题不要太长）。所以问题似乎出在目标和实验之间的双向关联上，但除此之外，我被这个错误绊住了。




Answer 1

查看数据库中的表定义。

describe target

我猜，它与您在问题中显示的createtable语句不同。特别是，列target\u id的定义可能不会显示为auto\u increment。

根据target\u id的定义，您可以使用

alter table target modify column target_id int not null auto_increment;