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工作,我有一个简单的实体对象和历史政策的EclipseLink历史政策不与MySQL生成的ID的
@Entity
@Customizer(MyHistoryPolicy.class)
@Table(name = "employee")
public class Employee {
@Id
@Column(name = "id")
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "name")
private String name;
... accessor methods
}
public class MyHistoryPolicy implements DescriptorCustomizer {
public void customize(ClassDescriptor descriptor) {
String historyTableName = descriptor.getTableName() + "_history";
HistoryPolicy policy = new HistoryPolicy();
policy.addHistoryTableName(historyTableName);
policy.addStartFieldName("start_date");
policy.addEndFieldName("end_date");
descriptor.setHistoryPolicy(policy);
}
}
插入一个新的对象正常工作。更新一个对象会导致id被设置为零。我看到来自Eclipselink的以下调试日志
UPDATE employee SET name = ? WHERE (id = ?)
bind => [test name, 2]
UPDATE employee_history SET end_date = ? WHERE ((end_date IS NULL) AND (id = ?))
bind => [2017-09-27 17:45:25.316, 2]
INSERT INTO employee_history (id, name, start_date) VALUES (?, ?, ?)
bind => [2, test name, 2017-09-27 17:45:25.316]
SELECT LAST_INSERT_ID()
注意历史记录表插入后的“SELECT LAST_INSERT_ID()”。历史记录表没有生成的标识,因此此查询返回零,并且此值将被覆盖到对象的标识字段中。原始ID丢失,这对应用程序有问题。
有没有人知道如何克服与Eclipselink与MySQL的这种短缺?
这是[EclipseLink中的已知错误](https://bugs.eclipse.org/bugs/show_bug.cgi?id=323023)。在2010年报道! 7年过去了,我想我有2次得到这个固定的机会[Buckley's和Nunn](https://en.wikipedia.org/wiki/Buckley_%26_Nunn)。 – bludginozzie