json_3层格式_数据源DataSet

例如下面这个方法，得到了一个视图的数据包含了省份城市店铺

public DataSet GetData()
        {
            try
            {
                StringBuilder sql = new StringBuilder("SELECT PROVINCE_ID,PROVINCE_NAME,CITY_ID,CITY_NAME,DEALER_ID,DEALER_NAME ");
                sql.Append(" FROM VIEW_P_C_Data  ");
                sql.Append(" WHERE  1=1 order by PROVINCE_NAME,CITY_NAME");
                DataSet ds = dbManager.Query(sql.ToString());
                return ds;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

首先获取到数据DataSet ds = GetData();

声明：HashSet<string> vehicle_p = new HashSet<string>();

然后循环ds

foreach (DataRow row in ds.Tables[0].Rows)
{

}

循环里做一个复制判断，因为省份是重复的，城市也是。一对多的关系。所以不同城市相同省份时，对于json结构只要添加一次省份

bool exist_province = vehicle_p.Add(row["PROVINCE_NAME"].ToString());
bool exist_city = vehicle_p.Add(row["CITY_ID"].ToString());

//当省份不存在时，第一次添加

if (exist_province)
{

}else{

//相同省份不同城市时，
if (exist_city)
{

}else{

//相同城市，不同店铺时

}

}

PS：全部代码

public List<Text_Drive_Dealer> GetAllDealer()
        {
            List<Text_Drive_Dealer> list = new List<Text_Drive_Dealer>();
            DataSet ds = GetData();
            HashSet<string> vehicle_p = new HashSet<string>();
            Text_Drive_Dealer t_dealer = null;
            List<Text_City> list_vm = null;
            Text_City vm = null;
            foreach (DataRow row in ds.Tables[0].Rows)
            {
                bool exist_province = vehicle_p.Add(row["PROVINCE_NAME"].ToString());
                bool exist_city = vehicle_p.Add(row["CITY_ID"].ToString());
               
                if (exist_province)
                {
                    //当省份不存在时，第一次添加
                    t_dealer = new Text_Drive_Dealer();
                    t_dealer.ProvinceID = row["PROVINCE_ID"].ToString();
                    t_dealer.ProvinceName = row["PROVINCE_NAME"].ToString();

                    //第一次添加城市
                    vm = new Text_City();
                    vm.CityID = row["CITY_ID"].ToString();
                    vm.CityName = row["CITY_NAME"].ToString();
                    //第一次添加该城市的特约店
                    Text_dealer td = new Text_dealer();
                    td.DealerID= row["DEALER_ID"].ToString();
                    td.DealerName = row["DEALER_NAME"].ToString();
                    List<Text_dealer> list_td = new List<Text_dealer>();
                    list_td.Add(td);
                    vm.text_dealer = list_td;
                    list_vm = new List<Text_City>();
                    list_vm.Add(vm);

                    t_dealer.TextDrive_City = list_vm;   
                    list.Add(t_dealer);
                }
                else
                {
                    
                    if (exist_city)
                    {
                        //第一次添加城市跟特约店
                        vm = new Text_City();
                        vm.CityID = row["CITY_ID"].ToString();
                        vm.CityName = row["CITY_NAME"].ToString();

                        Text_dealer td = new Text_dealer();

                        td.DealerID = row["DEALER_ID"].ToString();
                        td.DealerName = row["DEALER_NAME"].ToString();

                        List<Text_dealer> list_td = new List<Text_dealer>();
                        list_td.Add(td);
                        vm.text_dealer = list_td;
                        t_dealer.TextDrive_City.Add(vm);
                    }
                    else
                    {
                        //已有城市，添加特约店
                        //Text_City vm = new Text_City();
                        Text_dealer td = new Text_dealer();
                        td.DealerID = row["DEALER_ID"].ToString();
                        td.DealerName = row["DEALER_NAME"].ToString();
                        vm.text_dealer.Add(td);
                        //t_dealer.TextDrive_City.Find().text_dealer=;
                       
                    }
                }
            }
            return list;
        }