一、使用JdbcUtils完成DQL操作
### --- 查询姓名为张百万的一条记录

public class TestJDBC02 {
    
    public static void main(String[] args) throws SQLException {
        
        //1.获取连接对象
        Connection connection = JDBCUtils.getConnection();
        
        //2.获取Statement对象
        Statement statement = connection.createStatement();
        String sql = "SELECT * FROM jdbc_user WHERE username = '张百万';";
        
        ResultSet resultSet = statement.executeQuery(sql);

        //3.处理结果集
        while(resultSet.next()){

            //通过列名 获取字段信息
            int id = resultSet.getInt("id");
            String username = resultSet.getString("username");
            String password = resultSet.getString("password");
            String birthday = resultSet.getString("birthday");
            System.out.println(id+" "+username+" " + password +" " + birthday);
        }

        //4.释放资源
        JDBCUtils.close(connection,statement,resultSet);
    }
}
二、sql语句
package com.yanqi.jdbc05;

import com.yanqi.jdbc05.JdbcUtils; import java.sql.*; public class JdbcDql { // 查询姓名为张百万的一条记录 public static void main(String[] args) throws SQLException { //1.获取连接 Connection connection = JdbcUtils.getConnection(); //2.创建Statement对象 Statement statement = connection.createStatement(); //3. 编写SQL String sql = "select * from jdbc_user where username = '张百万'"; ResultSet resultSet = statement.executeQuery(sql); //4.处理结果集 while(resultSet.next()){ // 通过列名的方式获取 int id = resultSet.getInt("id"); String username = resultSet.getString("username"); String password = resultSet.getString("password"); Date birthday = resultSet.getDate("birthday"); System.out.println(id + " : " + username + " : " + password + " : " + birthday ); } //5.释放资源 JdbcUtils.close(connection,statement,resultSet); } }

 
 
 
 
 
 
 
 
 

Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart
                                                                                                                                                   ——W.S.Landor