Jdbc

Posted 2021-01-31 nangongyibin

jdbc

• jdbc是什么 jdbc:java数据库连接.
• jdbc有什么用 jdbc可以适配市面上大多数数据库.我们使用java语言开发只要写一套程序就ok.
• jdbc怎么用 
  • [1]加载对应数据库的驱动 
  • [2]连接要操作的数据库 
  • [3]准备你要执行的sql语句 select * from info; 
  • [4]执行sql语句 返回一个结果 
  • [5]把结果数据取出来.

        @Test
        public void jdbcTest1() throws Exception {
            DriverManager.deregisterDriver(new Driver());
            Connection conn = DriverManager.getConnection("jdbc:mysql://47.105.71.243:3306/ngyb", "root", "123456");
            String sql = "select * from `order`";
            Statement statement = conn.createStatement();
            ResultSet resultSet = statement.executeQuery(sql);
            while (resultSet.next()) {
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                int price = resultSet.getInt(3);
                System.out.println(id + "--" + name + "--" + price);
            }
            resultSet.close();
            statement.close();
            conn.close();
        }
    }