java - 从特定行java开始查询

Question

我试图在特定数量的查询后获得结果，即

String sql="Select from mytable where sell_id = 
 '"+purchase_id+"'";
        java.sql.Statement stmt=conn.createStatement();
        java.sql.ResultSet res=stmt.executeQuery(sql);

        while(res > 4){ //this line is where i still couldn't figured out
          String quantity = res.getString("quantity");
          String item = res.getString("item_name");
          String price = res.getString("price");
        }

但它显示错误“二元运算符'>'的错误操作数类型”

| quantity | item   | price |
|    20    | soda   |   5$  |
|    10    | noodle |   7$  |
|     5    | water  |   3$  |
|    15    | gum    |   4$  |
|    14    | tissue |   2$  | 
|     2    | snack  |   6$  |

结果应该是这样的

|    14    | tissue |   2$  | 
|     2    | snack  |   6$  |

任何建议都会被接受

Answer 1

您可以使用一个计数器来检查条件，如下所示:

int counter=1;
while(res.next()){
  if(counter>4){
      String quantity = res.getString("quantity");
      String item = res.getString("item_name");
      String price = res.getString("price");
  }
  counter++;
}