java---数据库操作

Posted 2020-10-20 Yi_Warmth

连接数据库的代码：

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class main{

            public static void main(String[]args){

                     Connnection con;//声明Connection对象

                     String driver="com.mysql.jdbc.Driver";//驱动程序名

                     String url="jdbc:mysql://localhost:3306/sqltestdb";//url指向要访问的数据库名的mydata

                     String  user="root";

                     String password="123456";

                     //遍历查询结果集

                     try{

                            Class.forName(driver);

                            //getConnection方法连接数据库

                            con=DriverManager.getConnection(url,user,password);

                            if(!con.isClosed())

                                    System.out.println("Succeeded  connecting to the database");

                          //创建Statement对象来执行sql语句

                           Statement statement=con.createStatement();

                           String sql="select * from emp";// 要执行的sql语句

                           ResultSet rs=statement.excuteQuery(sql);   //ResultSet类用来存放结果集

                           System.out.println("--------------");

                           System.out.println("执行结果如下：");

                           System.out.println("---------------");

                           System.out.println("姓名"+"\t"+"职称");

                           System.out.println("--------------");

                           String job=null;

                           String id=null;

                            while(rs.next()){

                              //获取stuname这列数据

                              job=rs.getString("job");

                              id=rs.getString("ename"); 

                              System.out.println(job+"\t"+id);

                                }

                             rs.close();

                             con.close();

                            }catch(ClassNotFoundException e){

                                 System.out.println("sorry,i can‘t find driver");

                                 e.printStackTrace();

                                 }catch(SQLException e){

                                        e.printStacktrace();

                                            }catch(Exception e){

                                             e.printStackTrace();

                                             }

                                   finally{

                                    System.out.println("数据库成功获取到数据");

                                          }

                 }

}