JPA - 從參考表中刪除條目

我實現了具有組和權限的工作臺權限系統。參考表workbench_group_permissions_reference有引用，所以我可以輕鬆地添加和刪除組的權限。添加新的引用條目可以正常工作，但刪除不會。我沒有收到任何錯誤，但刪除後，數據庫中仍存在該引用。我使用的是PostgreSQL。JPA - 從參考表中刪除條目

這裏是我引用類：

@XmlRootElement 
@Entity 
@Table(name = "workbench_group_permissions_reference", uniqueConstraints = { 
     @UniqueConstraint(columnNames = { "workbenchgroupspermissions_id", "workbench_groups_id" }) }) 
public class WorkbenchGroupPermissionReferenceEntity extends BasicEntity { 

    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    private long id; 

    @ManyToOne 
    @JoinColumn(name = "workbenchgroupspermissions_id") 
    private WorkbenchPermissionEntity workbenchPermission; 

    @ManyToOne 
    @JoinColumn(name = "workbench_groups_id") 
    private WorkbenchGroupEntity workbenchGroup; 

    /** 
    * Empty constructor to make JPA happy. 
    */ 
    public WorkbenchGroupPermissionReferenceEntity() { 
    } 

    public long getId() { 
     return id; 
    } 

    public void setId(long id) { 
     this.id = id; 
    } 

    public WorkbenchPermissionEntity getWorkbenchPermission() { 
     return workbenchPermission; 
    } 

    public void setWorkbenchPermission(WorkbenchPermissionEntity workbenchPermission) { 
     this.workbenchPermission = workbenchPermission; 
    } 

    public WorkbenchGroupEntity getWorkbenchGroup() { 
     return workbenchGroup; 
    } 

    public void setWorkbenchGroup(WorkbenchGroupEntity workbenchGroup) { 
     this.workbenchGroup = workbenchGroup; 
    } 
}

這是我的刪除方法：

public void deleteWorkbenchGroupPermission(final WorkbenchGroupPermissionReferenceEntity workbenchGroupPermission) { 
    long id = workbenchGroupPermission.getId(); 
    super.delete(WorkbenchGroupPermissionReferenceEntity.class, id); 
}

而且super.delete方法：

protected void delete(final Class<?> type, final Object id) { 
    Object ref = this.em.getReference(type, id); 
    this.em.remove(ref); 
}

缺少什麼我在這裏？

來源

2017-07-01 Felix Hagspiel

份額爲你'super.delete（..）'方法的代碼。我們不知道它做什麼 – Ranjeet

可能的原因：https://stackoverflow.com/questions/34840903/silently-ignored-remove –

@Dark添加缺少的超級方法 –

Dragan的link in the comment指出我正確的方向。我試圖刪除引用，但擁有實體（WorkbenchGroupEntity）仍然有引用。我沒有什麼要解決的問題是首先從擁有實體移除的參照，然後再把刪除交叉引用實體：

WorkbenchGroupPermissionReferenceEntity permissionToRemove = new WorkbenchGroupPermissionReferenceEntity(); 
    for(WorkbenchGroupPermissionReferenceEntity permissionReference : existingGroupPermissions) { 
     Long permissionRefernceId = permissionReference.getId(); 
     if(permissionRefernceId.equals(permissionId)){ 
      permissionToRemove = permissionReference; 
     } else { 
      newGroupPermissions.add(permissionReference); 
     } 
    } 
    workbenchGroupEntity.setWorkbenchGroupPermissions(newGroupPermissions); 
    workbenchGroupControl.updateWorkbenchGroup(workbenchGroupEntity); 
    workbenchGroupPermissionsControl.deleteWorkbenchGroupPermission(permissionToRemove);

編輯： 正如上面提到的解決方案是爲主要原因刪除工作不正常，我犯了另一個愚蠢的錯誤：我將交叉引用實體的id與權限id的id比較，而不是權限id本身，因此從未找到引用。

更新檢查：

for (WorkbenchGroupPermissionReferenceEntity permissionReference : existingGroupPermissions) { 
     // here was the mistake 
     Long permissionReferenceId = permissionReference.getWorkbenchPermission().getId(); 
     if (permissionReferenceId.equals(permissionId)) { 
      permissionToRemove = permissionReference; 
     } else { 
      newGroupPermissions.add(permissionReference); 
     } 
    }

來源

2017-07-02 16:45:11

JPA - 從參考表中刪除條目

回答

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