我正在使用 Hibernate 和 MySql，今天我在我的一个表中设置了一个复合主键，如下所示:

DefSelfLearning

这个实体是 OneToMany with SelfLearning:

这是我的java实体:

@Entity
@Table(name = "defselflearning", catalog = "ats")
public class DefSelfLearning implements java.io.Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @EmbeddedId
    private DefSelfLearningKeys defSelfLearningKeys;
    private Ecu ecu;
    private String excelColumn;
    @JsonIgnore
    private Set<SelfLearning> selfLearnings = new HashSet<SelfLearning>(0);

    public DefSelfLearning() {
    }

    public DefSelfLearning(DefSelfLearningKeys defSelfLearningKeys, Ecu ecu) {
        this.defSelfLearningKeys = defSelfLearningKeys;
        this.ecu = ecu;
    }

    public DefSelfLearning(Ecu ecu, DefSelfLearningKeys defSelfLearningKeys, String excelColumn, Set<SelfLearning> selfLearnings) {
        this.ecu = ecu;
        this.defSelfLearningKeys = defSelfLearningKeys; 
        this.excelColumn = excelColumn;
        this.selfLearnings = selfLearnings;
    }

    @Id
    public DefSelfLearningKeys getDefSelfLearningKeys() {
        return this.defSelfLearningKeys;
    }

    public void setDefSelfLearningKeys(DefSelfLearningKeys defSelfLearningKeys) {
        this.defSelfLearningKeys = defSelfLearningKeys;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "id_ecu", nullable = false)
    public Ecu getEcu() {
        return this.ecu;
    }

    public void setEcu(Ecu ecu) {
        this.ecu = ecu;
    }

    @Column(name = "excelColumn", length = 2)
    public String getExcelColumn() {
        return this.excelColumn;
    }

    public void setExcelColumn(String excelColumn) {
        this.excelColumn = excelColumn;
    }

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "defSelfLearning")
    public Set<SelfLearning> getSelfLearnings() {
        return this.selfLearnings;
    }

    public void setSelfLearnings(Set<SelfLearning> selfLearnings) {
        this.selfLearnings = selfLearnings;
    }

}

复合键的类:

    @Embeddable
public class DefSelfLearningKeys implements Serializable {
    private static final long serialVersionUID = 1L;
    protected String parName;
    protected String description;
    protected String note;

    public DefSelfLearningKeys() {}

    public DefSelfLearningKeys(String parName, String description, String note) {
        this.parName = parName;
        this.description = description;
        this.note = note;
    }

    @Column(name = "parName", nullable = false, length = 15)
    public String getParName() {
        return this.parName;
    }

    public void setParName(String parName) {
        this.parName = parName;
    }

    @Column(name = "description", nullable = false, length = 100)
    public String getDescription() {
        return this.description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    @Column(name = "note", nullable = false, length = 100)
    public String getNote() {
        return this.note;
    }

    public void setNote(String note) {
        this.note = note;
    }
}

和自学类:

@Entity
@Table(name = "selflearning", catalog = "ats")
public class SelfLearning implements java.io.Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private int idSelfLearning;
    private Acquisition acquisition;
    private DefSelfLearning defSelfLearning;
    private String value;

    public SelfLearning() {
    }

    public SelfLearning(int idSelfLearning, Acquisition acquisition, DefSelfLearning defSelfLearning) {
        this.idSelfLearning = idSelfLearning;
        this.acquisition = acquisition;
        this.defSelfLearning = defSelfLearning;
    }

    public SelfLearning(int idSelfLearning, Acquisition acquisition, DefSelfLearning defSelfLearning, String value) {
        this.idSelfLearning = idSelfLearning;
        this.acquisition = acquisition;
        this.defSelfLearning = defSelfLearning;
        this.value = value;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "id_selfLearning", unique = true, nullable = false)
    public int getIdSelfLearning() {
        return this.idSelfLearning;
    }

    public void setIdSelfLearning(int idSelfLearning) {
        this.idSelfLearning = idSelfLearning;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "id_acquisition", nullable = false)
    public Acquisition getAcquisition() {
        return this.acquisition;
    }

    public void setAcquisition(Acquisition acquisition) {
        this.acquisition = acquisition;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
          @JoinColumn(name = "id_parName", nullable = false),
          @JoinColumn(name = "id_description", nullable = false),
          @JoinColumn(name = "id_note", nullable = false)
        })
    public DefSelfLearning getDefSelfLearning() {
        return this.defSelfLearning;
    }

    public void setDefSelfLearning(DefSelfLearning defSelfLearning) {
        this.defSelfLearning = defSelfLearning;
    }

    @Column(name = "value")
    public String getValue() {
        return this.value;
    }

    public void setValue(String value) {
        this.value = value;
    }
}

但是当我创建一个 defSelfLearning 时一切正常，但是当我创建一个 SelfLearning 时我收到 MysqlDataTruncation 异常:

Caused by: com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column 'id_parName' at row 1

这个错误已经足够解释了，但我没有找到问题出在哪里，这是自学创建的代码:

for (DefSelfLearning defSelfLearning:defSelfLearningList){
        SelfLearning selfLearning=new SelfLearning();
        String key = defSelfLearning.getExcelColumn()+index;
        String value = actualRowValues.get(key);
        selfLearning.setAcquisition(findByCarAndExcelRow(carServices.findById(acquisitionForm.getCar()), index));
        selfLearning.setDefSelfLearning(defSelfLearning);
        selfLearning.setValue(value);
        System.out.println(selfLearning.getDefSelfLearning().getDefSelfLearningKeys().getParName());
        selfLearningServices.create(selfLearning);

    }

你找到问题出在哪里了吗？谢谢

这是 defSelfLearning 的第一行，也是代码失败的地方

如果我手动设置它会起作用:

这是第一个代码的 java 调试屏幕，失败了:

最佳答案

您尝试在“id_parName”列中插入一个长度超过 15 的字符

关于java - 复合主键和数据截断错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33805465/