java-JDBC操作Mysql

package testJdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class test2 {
  public static void main(String[] args) throws SQLException, ClassNotFoundException {
    //1、加载驱动器
    String JDBCDriver = "com.mysql.jdbc.Driver";
    Class.forName(JDBCDriver);
    //2、连接数据库
    String url="jdbc:mysql://127.0.0.1:3306/school";  //链接数据的url
    String user="root"; //登录数据库的用户名
    String password="123456"; //用户的密码
    Connection conn = DriverManager.getConnection(url, user, password);
    Statement st = conn.createStatement();
    //一、查询sql
    String sql="select * from student";
      ResultSet rs = st.executeQuery(sql);
    System.out.println("SId"+" "+"Sname"+" "+"Sage"+" "+"Ssex");
    while (rs.next()) {
      System.out.println(rs.getString("SId")+" "+rs.getString("Sname")+" "+rs.getString("Sage")+" "+rs.getString("Ssex"));
    }
    /*//二、修改数据
    int update = st.executeUpdate("update student set Sname='xiaolizi' where SId=2");
    System.out.println("修改后成功的条数："+update);
    */
    //三、删除
    //st.execute("delete from student where SId='2'");
    //四、添加数据
//    String sql1 = "insert into student(SId,Sname,Sage,Ssex) values('4','郑','3','2')";
//    st.execute(sql1);
    //关闭连接
    conn.close();
    st.close();
    rs.close();
  }
}