java - 仅在某些记录上出现约束违规 spring JPA

Question

我收到依赖项实体的违反约束异常，但它只发生在旧记录上。我最后的更改是向名为 KPIBusiness 的父实体添加一个 mappedBy=kpi 属性。

我可以删除新创建的具有依赖关系的父实体，但不能删除旧的。

KPIBusiness.java:

@Entity
public class KPIBusiness extends KPI {

    private Long businessProcessId;
    private String businessProcess;

    private Long eventId;
    private String event;

    @OneToMany(mappedBy="kpi", fetch = FetchType.EAGER, cascade=CascadeType.ALL)   
    private Set<Dependency> dependencies;
}

依赖.java

@Entity
@Table(name="dependencies")
public class Dependency {
    @Id
    @GeneratedValue
    private Long did;

    public Long getDid() {
        return did;
    }

    public void setDid(Long did) {
        this.did = did;
    }   
    private AlertConstants.TRIGGER kpiType;

    private Long kpiId;

    @JsonIgnore
    @ManyToOne
    @JoinColumn(name="id", nullable=false)  
    private KPIBusiness kpi;
}

异常(exception):

Caused by: org.h2.jdbc.JdbcSQLException: Referentielle Integrität verletzt: "FKSKW30595DULXL90POB2K9KT3I: PUBLIC.KPIBUSINESS_DEPENDENCIES FOREIGN KEY(DEPENDENCIES_DID) REFERENCES PUBLIC.DEPENDENCIES(DID) (33)" Referential integrity constraint violation: "FKSKW30595DULXL90POB2K9KT3I: PUBLIC.KPIBUSINESS_DEPENDENCIES FOREIGN KEY(DEPENDENCIES_DID) REFERENCES PUBLIC.DEPENDENCIES(DID) (33)"; SQL statement: delete from dependencies where did=? [23503-196]

我正在使用这段代码:

repository.delete(currentKPI);
repository.flush();

现在我正在考虑使用这段代码:

currentKPI.setDependencies(new HashSet<Dependency>());
currentKPI = repository.save(currentKPI);
repository.flush();//HACK delete at first try
repository.delete(currentKPI);
repository.flush();

但是，currentKPI.setDependencies(dependencies); 似乎根本没有更新依赖项。我使用此代码尝试更改依赖项:

Set<Dependency> dependencies = new HashSet<Dependency>();
for(RemoteKPINames kpi : tcsDependencies.getValue()) {
    Dependency dependency = new Dependency();
    dependency.setKpiId(kpi.getId());
    dependency.setKpiType(kpi.getType());
    dependency.setKpi(data);
    dependencies.add(dependency);
}

log.info("Setting dependencies in data object #={}", dependencies.size());
data.setDependencies(dependencies);

Answer 1

EmployeeEntity.java

@Entity
@Table(name = "Employee")
public class EmployeeEntity implements Serializable
{
    private static final long serialVersionUID = -1798070786993154676L;
    @Id
    @Column(name = "ID", unique = true, nullable = false)
    private Integer           employeeId;
    @Column(name = "FIRST_NAME", unique = false, nullable = false, length = 100)
    private String            firstName;
    @Column(name = "LAST_NAME", unique = false, nullable = false, length = 100)
    private String            lastName;

    @OneToMany(cascade=CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name="EMPLOYEE_ID")
    private Set<AccountEntity> accounts;

    //Getters and Setters Ommited
}

AccountEntity.java

@Entity
@Table(name = "Account")
public class AccountEntity implements Serializable
{
    private static final long serialVersionUID = 1L;
    @Id
    @Column(name = "ID", unique = true, nullable = false)
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private Integer           accountId;
    @Column(name = "ACC_NO", unique = false, nullable = false, length = 100)
    private String            accountNumber;

    @OneToOne (mappedBy="accounts",  fetch = FetchType.LAZY)
    private EmployeeEntity employee;

}

查看上面 EmployeeEntity.java 源代码中的粗体行。它定义了“cascade=CascadeType.ALL”，它本质上意味着在 EmployeeEntity 上发生的任何更改也必须级联到 AccountEntity。如果您保存一个员工，那么所有关联的帐户也将保存到数据库中。如果您删除员工，则与该员工关联的所有帐户也将被删除。很简单。

但是如果我们只想级联只保存操作而不是删除操作怎么办。然后我们需要使用下面的代码明确指定它。

@OneToMany(cascade=CascadeType.PERSIST, fetch = FetchType.LAZY)
@JoinColumn(name="EMPLOYEE_ID")
private Set<AccountEntity> accounts;

现在只有当使用员工实例调用 save() 或 persist() 方法时，才会只保留帐户。如果在 session 上调用任何其他方法，其效果不会影响/级联到帐户。

JPA 级联类型

Java Persistence Architecture 支持的级联类型如下:

1. CascadeType.PERSIST :表示 save() 或 persist() 操作级联到相关实体。
2. CascadeType.MERGE : 表示合并相关实体拥有实体合并。
3. CascadeType.REFRESH :对 refresh() 做同样的事情操作。
4. CascadeType.REMOVE : 删除所有关联的相关实体删除拥有实体时的此设置。
5. CascadeType.DETACH :如果是“手动”，则分离所有相关实体分离”发生。
6. CascadeType.ALL :是上述所有级联的简写运营。