原始的JDBC操作

# 原始JDBC操作

1.查询数据

//注册驱动
Class.forName("com.mysql.jdbc.Driver");
//获得连接
Connection connection = DriverManger.getConnection("jdbc:mysql:///test,"root","root");
//获得statement
PreparedStatement statement = connection.prepareStatement("select * from user");
//执行查询
ResultSet resultSet = statement.executeQuery();
//遍历结果集
while(resultSet.next()){
    //封装实体
    User user = new User();
    user.setId(resultSet.getInt("id"));
    user.setUsername(resultSet.getString("username"));
    user.serPassword(resultSet.getString("password"));
    //user实体封装完毕
    System.out.printLn(user);
}
//释放资源
resultSet.close();
statement.close();
connection.close();

2.插入数据

//模拟实体对象
User user = new User();
user.setId(2);
user.setUsername("tom");
user,setPassword("123");

//注册驱动
Class.forName("com.mysql.jdbc.Driver");
//获得连接
Connection connection = DriverManager.getConnection("jdbc:mysql:///test","root","root");
//获得statement
PreparedStatement statement = connection.prepareStatement("insert into user(id,username,password)values(?,?,?)");
//设置占位符参数
statement.setInt(1,user.getId());
statement.setString(2,user.getUsername());
statement.setString(3,user.getPassword());

//执行更新操作
statement.executeUpdate();

//释放资源
statement.close();
connection.close();