Criteria API組合2實體

Question

我試圖使用@OneToOne帳戶和實體實體之間的關係來過濾數據。 我需要做的是搜索具有Account.glcode =「15」的Entry-s

這裏是我所做的，但它不工作。

Root<?> root = mainQuery.from(Entry.class); 
Predicate predicate = builder.conjunction(); 
Join<Entry,Account> entries = root.join("account"); 
predicate = builder.and((builder.equal(entries.get("glCode"),"15"))); 

我的入門級

@Entity 
public class Entry { 

@Id 
private Long id; 
......... 

@OneToOne 
@JoinColumn(name = "account_id", nullable = false) 
private Account account; 

這是Account類

@Entity 
public class Account { 

@Id @GeneratedValue 
private Long id; 
private Long glCode; 

誰能告訴我什麼，我做錯了什麼？

感謝

修訂

public PaginationResult getFilteredData(List<FilterConstraint> filters, Object classname) { 
    try { 
     CriteriaBuilder builder = em.getCriteriaBuilder(); 
     CriteriaQuery<?> mainQuery = builder.createQuery(classname.getClass()); 
     Root<?> root = mainQuery.from(GLJournalEntry.class); 
     Predicate predicate = builder.conjunction(); 

     Predicate enumPredicate = builder.conjunction(); 
     Predicate today = builder.conjunction(); 
     Predicate on = builder.conjunction(); 

     for (FilterConstraint constraint : filters) { 

      //IT is hard coded right now for testing purpose but should be customized for the future 
      if(constraint.getField().getValue().contains("-")){ 
       String[] items = constraint.getField().getValue().split("-"); 
       Join<GLJournalEntry,GLAccount> entries = root.join("glAccount"); 
       predicate = builder.and((builder.equal(entries.get("glCode"), constraint.getValues().getValue()))); 
       entries.getAttribute().toString(); 
       break; 
      } 

      switch (constraint.getOperator()) { 
       case AFTER: 
        predicate = builder.and(builder.greaterThan(root.get(constraint.getField().getValue()), constraint.getValues().getStartDate())); 
        break; 
       case BEFORE: 
        predicate = builder.and(builder.greaterThan(root.get(constraint.getField().getValue()), constraint.getValues().getStartDate())); 
        break; 
       case BETWEEN: 
        if (constraint.getField().getType() == FieldDataType.DATE) { 
         predicate = builder.and(builder.between(root.get(constraint.getField().getValue()), constraint.getValues().getStartDate(), constraint.getValues().getEndDate())); 
        } else if (constraint.getField().getType() == FieldDataType.INTEGER) { 
         predicate = builder.and(builder.between(root.get(constraint.getField().getValue()), Integer.valueOf(constraint.getValues().getMinValue()), Integer.valueOf(constraint.getValues().getMaxValue()))); 
        } else { 
         predicate = builder.and(builder.between(root.get(constraint.getField().getValue()), constraint.getValues().getMinValue(), constraint.getValues().getMaxValue())); 
        } 
        break; 
       case EMPTY: 
        predicate = builder.and(builder.isEmpty(root.get(constraint.getField().getValue()))); 
        break; 
       case EQUALS: 
        if (constraint.getField().getType() == FieldDataType.ENUM) { 

         Object enumV = null; 

         if (constraint.getValues().getEnumValue().size() > 1) { 

          List<Predicate> predicates = new ArrayList<>(); 
          for (EnumValue enumValue : constraint.getValues().getEnumValue()) { 


           for (Field f : classname.getClass().getDeclaredFields()) { 
            if (f.getName().equals(constraint.getField().getValue())) { 
             System.out.println("T"); 
             Class<?> clz = f.getType(); 
             Object[] consts = clz.getEnumConstants(); 
             for (int i = 0; i < consts.length - 1; i++) { 
              if (consts[i].toString().equals(enumValue.getValue())) { 
               enumV = consts[i]; 
               break; 
              } 
             } 
            } 
           } 
           predicates.add(builder.equal(root.get(constraint.getField().getValue()), enumV)); 
          } 

          enumPredicate = builder.and(builder.or(predicates.toArray(new Predicate[]{}))); 
          break; 
         } 

         for (Field f : classname.getClass().getDeclaredFields()) { 
          if (f.getName().equals(constraint.getField().getValue())) { 
           System.out.println("T"); 
           Class<?> clz = f.getType(); 
           Object[] consts = clz.getEnumConstants(); 
           for (int i = 0; i < consts.length - 1; i++) { 
            if (consts[i].toString().equals(constraint.getValues().getEnumValue().get(0).getValue())) { 
             enumV = consts[i]; 
             break; 
            } 
           } 
          } 
         } 


         enumPredicate = builder.equal(root.get(constraint.getField().getValue()), enumV); 
         break; 
        } 
        predicate = builder.and(builder.equal(root.get(constraint.getField().getValue()), constraint.getValues().getValue())); 
        break; 
       case LESS_THAN: 
        predicate = builder.and(builder.lessThan(root.get(constraint.getField().getValue()), constraint.getValues().getValue())); 
        break; 

       case MORE_THAN: 
        predicate = builder.and(builder.greaterThan(root.get(constraint.getField().getValue()), constraint.getValues().getValue())); 
        break; 
       case NOT_EMPTY: 
        predicate = builder.and(builder.isNotEmpty(root.get(constraint.getField().getValue()))); 
        break; 
       case ON: 
        on = builder.between(root.get(constraint.getField().getValue()), DateUtils.getFirstSecondOfDate(constraint.getValues().getStartDate()), DateUtils.getLastSecondOfDate(constraint.getValues().getStartDate())); 
        break; 
       case STARTS_WITH: 

       case TODAY: 
        today = builder.and(builder.between(root.get(constraint.getField().getValue()), DateUtils.getFirstSecondOfDate(new Date()), DateUtils.getLastSecondOfDate(new Date()))); 
        break; 
      } 


     } 


     CriteriaQuery<Long> cq = builder.createQuery(Long.class); 
     cq.select(builder.count(cq.from(classname.getClass()))); 
     em.createQuery(cq); 
     cq.where(predicate, enumPredicate, today, on); 
     Long count = em.createQuery(cq).getSingleResult(); 

     mainQuery.where(predicate, enumPredicate, today, on); 


     //Count for pagination 
     TypedQuery<?> q = em.createQuery(mainQuery); 
     q.setMaxResults(filters.get(0).getCount()); 
     int firstResult = filters.get(0).getPage() * filters.get(0).getCount() - filters.get(0).getCount(); 
     q.setFirstResult(firstResult); 


     PaginationResult result = new PaginationResult(); 
     result.setData((List<Client>) q.getResultList()); 
     result.setMaxResults(count); 

     System.out.println(result.getData().size()); 

     return result; 
    } catch (Exception e) { 
     System.out.println(e.getMessage()); 
     return null; 
    } 

} 

Answer 1

您的glCode參數是一個字符串，但必須是長。並使用更好的ParameterExpression，

例子：

public List<Entry> findEntryByGlCode(Long glCode) { 
    CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder(); 

    final CriteriaQuery<Entry> query = criteriaBuilder.createQuery(Entry.class); 
    final Root<Entry> root = query.from(Entry.class); 

    Join<Entry, Account> join = root.join("account"); 
    ParameterExpression<Long> glcodeParameter = criteriaBuilder.parameter(Long.class, "glCode"); 
    Predicate equal = criteriaBuilder.equal(join.get("glCode"), glcodeParameter); 

    query.where(equal); 
    query.select(root); 

    return entityManager.createQuery(query).setParameter("glCode", glCode).getResultList(); 
}