@Entity
@Table(name="T_BILL_ACCT_ITEM")
@NamedQuery(name="TBillAcctItem.findAll", query="SELECT t FROM TBillAcctItem t")
 
public class TBillAcctItem implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @Column(name="ACCT_ITEM_ID")
    private long acctItemId;
    
    @Column(name="ACCT_ID")
    private long acctId;
    
    @Column(name="BILLING_CYCLE_ID")
    private String billingCycleId;
    
    @Column(name
 
="PRODUCT_ID")
    private String productId;
    
    @Column(name="SERVICE_ID")
    private String serviceId;
    
    @Column(name="ACCT_ITEM_CODE")
    private String acctItemCode;
    
    @Column(name="ORIGINAL_AMOUNT")
    private int originalAmount;
    
    @Column(name="CDR_DISCOUNT")
    private
 
 int cdrDiscount;
    
    @Column(name="ACCT_DISCOUNT")
    private int acctDiscount;
    
    @Column(name="RECE_AMOUNT")
    private int receAmount;
    
    @Column(name="REAL_AMOUNT")
    private int realAmount;
    
    @Column(name="CHARGE_OFF_SOURCE")
    private int chargeOffSource;
    
    @Column(name="STATE")
    private int state;

但是我現在需要查詢出來的信息是這樣的一個pojo類：(因為int類型的值不能為空，所以我需要將字段定義為 java.long.Integer類型)

public class ProductBillInfo implements Serializable{

    private static final long serialVersionUID = 1L;
    private String productId;//產品標識
    private String serverId;//服務標示
    private Integer realAmount;//實收金額（sum求和）
    private Integer receAmount;//應收金額（sum求和）
    private int state;//賬目狀態
    private String billingCycle;//賬期(月)

因為hibernate要查詢的對象是要和表結構一一映射的，現在求和字段這些個是映射不了的， 之前的方法就有問題了。 找了很多看了hibernate的API 找到這個東西。 如下：

        StringBuffer b = new StringBuffer();  
    //... 省略SQL拼接代碼  
    String sql = b.toString();  
    SQLQuery query = session.createSQLQuery(sql); 
    query.addScalar("productId", StandardBasicTypes.STRING);//要查詢出來的字段、類型
    List<ProductBillInfo> lnfo =query.list();

下面是我用到的查詢pojo的方法中的實現:

@SuppressWarnings("unchecked")
    public List<ProductBillInfo> findByAcctIdAndCycle1(long acctId,
            String cycleBegin, String cycleEnd, int state){
        
        List<String> cycles = DateUtil.getAllCycle(cycleBegin, cycleEnd);
        StringBuffer buf = new StringBuffer();
        buf.append("select t.PRODUCT_ID as productId , t.SERVICE_ID as  serviceId ," +
        "sum(t.REAL_AMOUNT) as  realAmount  ,sum(t.RECE_AMOUNT) as  receAmount ," +
        "t.STATE as state ,t.BILLING_CYCLE_ID as  billingCycleId " +
        " from T_BILL_ACCT_ITEM t where t.STATE= ‘" + state + "‘ AND t.ACCT_ID=‘" + acctId + "‘ AND t.BILLING_CYCLE_ID in (");
        StringBuffer bf = new StringBuffer();
        for(String id : cycles){
               if(bf.toString().equals("")){
                   bf.append("‘"+id+"‘");
               } else{
                   bf.append(","+"‘"+id+"‘");
               }
        }
        buf.append(bf.toString());
        buf.append(") GROUP BY t.PRODUCT_ID,t.BILLING_CYCLE_ID,t.SERVICE_ID");
        
        SQLQuery query = getSession().createSQLQuery(buf.toString());  
        query.addScalar("productId", StandardBasicTypes.STRING);
        query.addScalar("serviceId", StandardBasicTypes.STRING);
        query.addScalar("realAmount", StandardBasicTypes.INTEGER);
        query.addScalar("receAmount", StandardBasicTypes.INTEGER);
        query.addScalar("state", StandardBasicTypes.INTEGER);
        query.addScalar("billingCycleId", StandardBasicTypes.STRING);
        
        query.setResultTransformer(Transformers.aliasToBean(ProductBillInfo.class));  
        List<ProductBillInfo> lnfo =query.list();
        return lnfo;
    }

註：示例中addScalar及setResultTransformer很關鍵，我在使用的時候還報了一個錯(原因是在實體中需要有一個無參構造函數)，否則錯誤如下：

org.hibernate.HibernateException: Could not instantiate resultclass:com.eastelsoft.framework.formbean.interfaceBean.ProductBillInfo

public static void main(String[] args) {
        List<String> c = new ArrayList<String>();
        c.add("1");c.add("2");c.add("3");
        StringBuffer bf = new StringBuffer();
        for(String id : c){
               if(bf.toString().equals("")){
                   bf.append("‘"+id+"‘");
               } else{
                   bf.append(","+"‘"+id+"‘");
               }
            }
        System.out.println(bf.toString());
    }

打印結果是： ‘1‘,‘2‘,‘3‘

hibernate使用setResultTransformer()將SQL查詢結果放入集合中