java的休眠標準錯誤

Question

這裏的數據庫模式：

Table A:    public class A { 
id integer,    B objectB; 
comment varchar(30),  String comment;   
id_B integer   } 

Table B:    public class B { 
id integer,    C objectC; 
comment varchar(20),  String comment; 
network integer   } 

Table C:    public class C { 
id       Integer id; 
name varchar(30)   String name; 
         } 

現在我需要創建檢查表C正確的「ID」和「評論」表B.我試圖做一個標準：

Criteria criteria = getSession().createCriteria(A.class); 
criteria.createCriteria("objectB") 
     .createCriteria("objectC").add(Restrictions.idEq(networkID)); 

//gives org.hibernate.QueryException: duplicate association path: objectB error 
if (comment != null && comment.length() > 0) { 
    criteria.createCriteria("objectB") 
      .add(Restrictions.like("comment", "%" + comment + "%")); 
} 

//second approach gives me no error but does not work, means I receive the wrong results 
if (comment != null && comment.length > 0) { 
    criteria.add(Restrictions.like("comment", "%" + comment + "%")); 
} 

Answer 1

我不認爲它喜歡的代碼來創建對象Criteria爲objectB。代碼中還有一個語法錯誤。

修訂

Criteria criteria = getSession().createCriteria(A.class); 
Criteria criteriaB = criteria.createCriteria("objectB"); 
Criteria criteriaC = criteriaB.createCriteria("objectC"); 
criteriaB.add(Restrictions.like("comment", "%" + comment + "%")); 
criteriaC.add(Restrictions.idEq(networkID)); 

語法問題

Criteria criteria = getSession().createCriteria(A.class); 
criteria.createCriteria("objectB") 
     .createCriteria("objectC").add(Restrictions.idEq(networkID)); 

//Syntax error occurs here, missing add 
criteria.createCriteria("objectB") 
     .(Restrictions.like("comment", "%" + comment + "%")); 

//Fix 
criteria.createCriteria("objectB").add(Restrictions.like("comment", "%" + comment + "%")); 

Answer 2

試試這個。你並不需要調用個createCriteria（「對象B」）兩次

Criteria criteria = getSession().createCriteria(A.class); 
    criteria.createCriteria("objectB").createCriteria("objectC").add(Restrictions.idEq(networkID)).add(Restrictions.like("comment", "%" + comment + "%")); 

if (comment != null && comment.length > 0) { 
    criteria.createAlias("objectB", "b") 
    criteria.add(Restrictions.like("b.comment", "%" + comment + "%")); 
}