另类的方法重载(小白的感慨)。

在做的项目中有个这样的方法。返回的是一个HashMap的集合。

public static  HashMap<Object, Object> findTotalDuebillBalance(Database db,
       String pcCode, String districtCode, String ccCode,
       String studentName,String studentCode) throws Exception
  {
    String sql = "select d.studentCode,sum(duebillBalance) as totalDuebillBalance " +
           "\n from duebill d" +
           "\n left join StudentRelation sr on sr.studentCode=d.studentCode" +
           "\n left join CountyCenter cc on cc.ccCode=sr.ccCode" +
           "\n where 1=1";
   
    if(!ccCode.equals(""))
        sql += "\n and sr.ccCode='"+ccCode+"'";
      else if(!districtCode.equals(""))
        sql += "\n and   exists (select 1 from CountyCenter cc where cc.ccCode=dd.deductCcCode and cc.pccCode like '"+districtCode+"%')";
      else if(!pcCode.equals(""))
        sql += "\n and sr.pcCode='"+pcCode+"'";
      if(!studentName.equals(""))
        sql += "\n and sr.studentName like '"+studentName+"%'";
      if(!studentCode.equals(""))
          sql += "\n and sr.studentCode = '"+studentCode+"'";
     
      sql += "\n group by d.studentCode";
     
    //执行查询
    DataSet ds = db.executeQuery(sql);
    HashMap<Object, Object> duebillMap = new HashMap<Object, Object>();
    for (int i=0;i<ds.size();i++)
    {
     duebillMap.put(ds.getString(i, "studentCode"),ds.getDouble(i, "totalDuebillBalance"));
    }
    return duebillMap;
  }

 

然后在bo中调用时候，传入参数时候。

第一种调用

DaoMyTest.findTotalDuebillBalance(db,"","","","","",studentCode)；

第二种调用

DaoMyTest.findTotalDuebillBalance(db,pcCode,districtCode,ccCode,"");

 

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这个和以前学习的时候学的方法重载很像，不过这种写法更倾向于简洁的应用，不至于写很多方法。业务理解上会有点困难。