休眠標準assotiated對象

Question

我有DTO的下一個結構對象：

public class MainDTO implements Serializable { 
    private Long mainId; 
    private String name; 
    ... //some other fields 
    private boolean disabled; 

    @ManyToOne() 
    @JoinColumn(name = "root_id") 
    private RootDTO root; 

    @ManyToOne(fetch = FetchType.LAZY) 
    @JoinColumn(name = "child_id", updatable = false, referencedColumnName = "child_id") 
    @Cascade(value = { CascadeType.ALL, CascadeType.DELETE_ORPHAN }) 
    private ChildDTO child; 

    ... 
} 

public class RootDTO implements Serializable { 
    ... //some other fields 
    private boolean disabled; 

    ... 
} 


public class ChildDTO implements Serializable { 
    private Long childId; 
    ... //some other fields 
    private boolean disabled; 

    @ManyToOne() 
    @JoinColumn(name = "info_id") 
    private InfoDTO info; 

    ... 
} 

public class InfoDTO implements Serializable { 
    private Long infoId; 
    ... //some other fields 
    private boolean disabled; 

    ... 
} 

我需要填寫Map<String, Map<Long, Long>>（<name from MainDTO, <mainId from MainDTO, infoId from InfoDTO >>）與下一個限制：

MainDTO.disabled =假，

MainDTO.root！= null，

MainDTO.root.disabled = false，

MainDTO.child.disabled =假，

MainDTO.child.info！= NULL，

MainDTO.child.info.disabled =假

這裏是我寫的代碼，但從InfoDTO中選擇infoId：

Criteria rootCriteria = getSession().createCriteria(
     MainDTO.class); 

// check that root is enabled 
rootCriteria.createCriteria("root", "root").add(
    Restrictions.eq("disabled", false)); 

// check that child is enabled 
Criteria childCriteria = rootCriteria 
    .createCriteria("child", "child") 
    .add(Restrictions.eq("disabled", false)) 
    .add(Restrictions.isNotNull("info")); 

// check that info is enabled 
childCriteria 
    .createCriteria("info", "info") 
    .add(Restrictions.eq("disabled", false)); 

ProjectionList rootProjection = Projections.projectionList() 
    .add(Projections.property("mainId")) 
    .add(Projections.property("name")) 
    .add(Projections.property("child.info")); //HOW TO SELECT ONLY ID?? 
rootCriteria.setProjection(rootProjection); 
rootCriteria.add(Restrictions.eq("disabled", false)) 
    .add(Restrictions.isNotNull("root")) 
    .add(Restrictions.isNotNull("child")); 

非常感謝！

Answer 1

首先，調用實體DTO真的很讓人困惑。

現在關於你的問題，你應該使用您在突起劃分

ProjectionList rootProjection = 
    Projections.projectionList() 
       .add(Projections.property("mainId")) 
       .add(Projections.property("name")) 
       .add(Projections.property("info.infoId")); 

此外，考慮到你正在做一個內部聯接到根目錄和子目錄的別名，最後兩個限制是沒有必要的：內部連接已經確保這些不是null。