JDBC入门

public static void main(String[] args) throws Exception {
//注册数据库驱动
//DriverManager.registerDriver(new Driver());
//执行Driver中的静态代码块，避免冗余代码执行
Class.forName(“com.mysql.jdbc.Driver”);
//数据库的位置
String url = “jdbc:mysql://localhost:3306/day04_db”;
//账号
String user = “root”;
//密码
String password = “root”;
//创建Connection连接通道
Connection conn = DriverManager.getConnection(url,user,password);
//通过conn对象方法获取sql语句的对象
Statement st = conn.createStatement();
//输入要发送给sql执行的语句
String sql = “select * from user”;
//接收执行sql语句后返回的结果
ResultSet rs = st.executeQuery(sql);
while(rs.next()){
int id = rs.getInt(“id”);
String username = rs.getString(“username”);
String pwd = rs.getString(“password”);

        System.out.println(id+"==="+username+"===="+pwd);
    }

    rs.close();
    st.close();
    conn.close();
}