Hibernate @OneToOne 无法添加或更新子行：外键约束

Question

我正在使用 JPA、Hibernate、Spring 和 MySQL

无法添加或更新子行：外键约束失败（ db1 ，CONSTRAINT stock_detail FOREIGN KEY（ FK_STOCK_ID ）REFERENCES stock （ STOCK_ID STOCK_ID ）

创建脚本

 CREATE TABLE IF NOT EXISTS `stock` (
  `STOCK_ID` int(10) unsigned NOT NULL,
  `STOCK_CODE` varchar(10) NOT NULL,
  `STOCK_NAME` varchar(20) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=86 DEFAULT CHARSET=utf8;

CREATE TABLE IF NOT EXISTS `stock_detail` (
  `STOCK_ID` int(10) unsigned NOT NULL,
  `COMP_NAME` varchar(100) NOT NULL,
  `COMP_DESC` varchar(255) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=72 DEFAULT CHARSET=utf8;

ALTER TABLE `stock`
  ADD PRIMARY KEY (`STOCK_ID`) USING BTREE,
  ADD UNIQUE KEY `UNI_STOCK_NAME` (`STOCK_NAME`),
  ADD UNIQUE KEY `UNI_STOCK_CODE` (`STOCK_CODE`) USING BTREE;

ALTER TABLE `stock_detail`
  ADD PRIMARY KEY (`STOCK_ID`) USING BTREE;

ALTER TABLE `stock`
  MODIFY `STOCK_ID` int(10) unsigned NOT NULL AUTO_INCREMENT,AUTO_INCREMENT=86;

ALTER TABLE `stock_detail`
  MODIFY `STOCK_ID` int(10) unsigned NOT NULL AUTO_INCREMENT,AUTO_INCREMENT=72;

ALTER TABLE `stock_detail`
  ADD CONSTRAINT `FK_STOCK_ID` FOREIGN KEY (`STOCK_ID`) REFERENCES `stock` (`STOCK_ID`);

股票实体

@Entity
@Table(name = "stock")
@XmlRootElement
@Component("astock")
@NamedQueries({
    @NamedQuery(name = "Stock.findAll", query = "SELECT s FROM Stock s"),
    @NamedQuery(name = "Stock.findByStockId", query = "SELECT s FROM Stock s WHERE s.stockId = :stockId"),
    @NamedQuery(name = "Stock.findByStockCode", query = "SELECT s FROM Stock s WHERE s.stockCode = :stockCode"),
    @NamedQuery(name = "Stock.findByStockName", query = "SELECT s FROM Stock s WHERE s.stockName = :stockName")})
public class Stock implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "STOCK_ID")
    private Integer stockId;
    @Basic(optional = false)

    @Size(min = 1, max = 10)
    @Column(name = "STOCK_CODE")
    private String stockCode;
    @Basic(optional = false)

    @Size(min = 1, max = 20)
    @Column(name = "STOCK_NAME")
    private String stockName;
    @OneToOne(cascade = CascadeType.ALL, mappedBy = "stock")
    private StockDetail stockDetail;

StockDetail实体

@Entity
@Table(name = "stock_detail")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "StockDetail.findAll", query = "SELECT s FROM StockDetail s"),
    @NamedQuery(name = "StockDetail.findByStockId", query = "SELECT s FROM StockDetail s WHERE s.stockId = :stockId"),
    @NamedQuery(name = "StockDetail.findByCompName", query = "SELECT s FROM StockDetail s WHERE s.compName = :compName"),
    @NamedQuery(name = "StockDetail.findByCompDesc", query = "SELECT s FROM StockDetail s WHERE s.compDesc = :compDesc")})
public class StockDetail implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "STOCK_ID")
    private Integer stockId;
    @Basic(optional = false)

    @Size(min = 1, max = 100)
    @Column(name = "COMP_NAME")
    private String compName;

    @Basic(optional = false)
    @Size(min = 1, max = 255)
    @Column(name = "COMP_DESC")
    private String compDesc;
    @JoinColumn(name = "STOCK_ID", referencedColumnName = "STOCK_ID")
    @OneToOne(cascade = CascadeType.ALL)
    private Stock stock;

我是如何努力挽救它的。

    Stock StockServices = (Stock) applicationContext.getBean("astock");

    Stock stock = new Stock();
    stock.setStockCode("123");
    stock.setStockName("AAPL");

    StockDetail stockDetail = new StockDetail();
    stockDetail.setCompName("Apple");
    stockDetail.setCompDesc("A hardware and software company");

    stockDetail.setStock(stock);
    stock.setStockDetail(stockDetail);

    sessionFactory.getCurrentSession().saveOrUpdate(stock);

Answer 1

同意接受的答案。

不过，如果您想在子表中坚持使用外键作为主键，请在子表上使用Foreign Key Generator 。 这样，我们可以减少创建太多唯一ID所需的数据库引擎开销。

请参阅： ForeignKeyGeneratorUsage

Answer 2

你的问题是，您尝试使用stock_detail.STOCK_ID既作为PRIMARY KEY的stock_detail和FOREIGN KEY从股市和你为他们分配不同的自动递增值。

当Hibernate保存它们时，它将尝试保存STOCK_ID =86 stock_detail和STOCK_ID=72 stock_detail ，这会破坏外键合同。

而是在您的stock_detail表中创建一个单独的主键，例如stock_detail_id并将stock_id为单独的列。

Answer 3

接受的答案没有提供最佳解决方案。 出于此处概述的原因，应保留使用stock.STOCK_ID作为stock_detail的主/外键的方法。 在 JPA 中，也支持这种方法，只需使用本教程第 4 节中概述的@PrimaryKeyJoinColumn和@MapsId注释