如何为多个实体编写 HQL 查询答案

【问题标题】：How to write HQL Query for multiple entities如何为多个实体编写 HQL 查询
【发布时间】：2015-06-24 05:39:26
【问题描述】：

我正在尝试编写一个 HQL 查询来获取记录的 id。但查询给了我这个错误

org.hibernate.QueryException：无法解析属性：CompanyMaster of：EntityPack.UserTypeMenuBarComp [从 EntityPack.UserTypeMenuBarComp 中选择 userTypeMenuBar.userMenuBar.menuBarId 作为 UserTypeMenuBarComp 其中 UserTypeMenuBarComp.companyGroupMaster.companyGroupId=4 和 UserTypeMenuBarComp.CompanyMaster.companyMasterId=2 和UserTypeMenuBarComp.userTypeMenuBar.userType.userTypeId=2]

这是我的查询：

select userTypeMenuBar.userMenuBar.menuBarId FROM UserTypeMenuBarComp as UserTypeMenuBarComp where UserTypeMenuBarComp.companyGroupMaster.companyGroupId=" + 
    UsercompGid(LoginImpl.masterid) +
     " and UserTypeMenuBarComp.CompanyMaster.companyMasterId=" + 
    Usercompid(LoginImpl.masterid) +
     " and UserTypeMenuBarComp.userTypeMenuBar.userType.userTypeId=" + 
    LoginImpl.usertypid + ""

这里是实体类（UserTypeMenuCompany）：

@Entity
public class UserTypeMenuCompany implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Basic(optional = false)
    @Column(name = "User_Type_Menu_Company_Id")
    private Integer userTypeMenuCompanyId;
    @Basic(optional = false)
    @Column(name = "Status")
    private String status;
    @Column(name = "Markers")
    private String markers;
    @ManyToOne(optional = false)
    private UserTypeMenu userTypeMenu;
    @ManyToOne(optional = false)
    private CompanyMaster companyMaster;
    @JoinColumn(name = "Company_Group_Id", referencedColumnName = "Company_Group_Id")
    @ManyToOne(optional = false)
    private CompanyGroupMaster companyGroupMaster;

（用户类型菜单栏）

public class UserTypeMenuBar implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Basic(optional = false)
    @Column(name = "User_Type_Menu_Bar_Id")
    private Integer userTypeMenuBarId;
    @Basic(optional = false)
    @Column(name = "Status")
    private String status;
    private String markers;
    //@JoinColumn(name = "User_Type_Id", referencedColumnName = "User_Type_Id")
    @ManyToOne(optional = false)
    private UserType userType;
   // @JoinColumn(name = "Menu_Bar_Id", referencedColumnName = "Menu_Bar_Id")
    @ManyToOne(optional = false)
    private UserMenuBar userMenuBar;

（用户菜单栏）

public class UserMenuBar implements Serializable  {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Basic(optional = false)
    @Column(name = "Menu_Bar_Id")
    private Integer menuBarId;
    @Basic(optional = false)
    @Column(name = "Menu_Bar_Desc")
    private String menuBarDesc;
    @Basic(optional = false)
    @Column(name = "Status")
    private String status;

    @Basic(optional = false)
    @Column(name = "Markers")
    private String markers;

和（用户类型）

public class UserType {
        @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Basic(optional = false)
    @Column(name = "User_Type_Id")
    private Integer userTypeId;
    @Basic(optional = false)
    @Column(name = "User_Type")
    private String userType;
    @Basic(optional = false)
    @Column(name = "User_Type_Desc")
    private String userTypeDesc;
    @Basic(optional = false)
    @Column(name = "Status")
    private String status;
      @Basic(optional = false)
    @Column(name = "Markers")
    private String markers;

【问题讨论】：

你好@Chirag Kamat，你解决了你在问题中提到的错误还是你仍然遇到错误？？

标签： hibernate orm hql hibernate-mapping

【解决方案1】：

除了@Popandopolos 的回答，我认为在您的查询中使用 join 会对您有所帮助。

请访问Associations and joins 上的休眠文档以获取更多信息

如果您使用的是休眠查询，那么我认为您的查询如下所示

select userTypeMenuBar.userMenuBar.menuBarId FROM UserTypeMenuBarComp as UserTypeMenuBarComp 
inner join UserTypeMenuBarComp.companyGroupMaster 
inner join UserTypeMenuBarComp.CompanyMaster
inner join UserTypeMenuBarComp.userTypeMenuBar.userType
where UserTypeMenuBarComp.companyGroupMaster.companyGroupId=" + 
    UsercompGid(LoginImpl.masterid) +
     " and UserTypeMenuBarComp.CompanyMaster.companyMasterId=" + 
    Usercompid(LoginImpl.masterid) +
     " and UserTypeMenuBarComp.userTypeMenuBar.userType.userTypeId=" + 
    LoginImpl.usertypid + ""

【讨论】：

【解决方案2】：

根据HQL referenceJava 类和属性区分大小写

除了 Java 类和属性的名称，查询不区分大小写。所以 SeLeCT 和 sELEct 和 SELECT 一样，但是 org.hibernate.eg.FOO 不是 org.hibernate.eg.Foo， foo.barSet 不是 foo.BARSET。

所以您需要在此处修复您的查询： UserTypeMenuBarComp.companyMaster.companyMasterId - companyMaster 应该以小写字母 c

开头

【讨论】：