1 //stmt.executeUpdate 执行成功后，返回值为受影响行数，对DDL不能判断其0或1来断定是否执行成功
1 //ResultSet 2 //stmt.executeQuery(sql):执行DQL语句，返回ResultSet对象 3 4 5 //获取查询结果 6 boolean next();//将光标移到下一行，并判断下一行是否为有效行 7 xxx getXxx(参数);//获取数据，xxx为数据类型，如：int getInt(参数); 8 9 10 import java.sql.*; 11 //获取表中的数据，并打印 12 public class JDBCdemo { 13 public static void main(String[] args) throws Exception { 14 //1.注册驱动 15 Class.forName("com.mysql.cj.jdbc.Driver"); 16 17 //2.获取连接 18 String url = "jdbc:mysql://127.0.0.1:3306/db1"; 19 String username = "root"; 20 String password = "1234"; 21 Connection conn = DriverManager.getConnection(url,username,password); 22 23 //定义sql 24 String sql = "select * from account"; 25 26 //获取statement对象 27 Statement statement = conn.createStatement(); 28 29 //执行sql 30 ResultSet rs = statement.executeQuery(sql); 31 32 //处理结果 33 while(rs.next()){ 34 int id = rs.getInt(1); 35 String name = rs.getString(2); 36 double money = rs.getDouble(3); 37 System.out.println(id); 38 System.out.println(name); 39 System.out.println(money); 40 System.out.println("==========================="); 41 } 42 43 //释放资源 44 rs.close(); 45 statement.close(); 46 conn.close(); 47 48 } 49 50 }