数据库的修改

import java.sql.*;

 

import java.util.Scanner;

 

public class jdbcupdate {

    public static void main(String[]args) {

        final String URL = "jdbc:mysql://localhost:3306/test";

        final String USERNAME = "root";

        final String PWD = "12345";

        Connection connection = null;

        Statement  stmt = null;

        Scanner con=new Scanner(System.in);

        String idnumber;

        String classname;

        String teachername;

        String didian;

         

        //idnumber=con.nextLine();

        classname=con.nextLine();

        teachername=con.nextLine();

        //didian=con.nextLine();

        try {

            // a.导入驱动，加载具体的驱动类

            Class.forName("com.mysql.jdbc.Driver");// 加载具体的驱动类

            // b.与数据库建立连接

            connection = DriverManager.getConnection(URL, USERNAME, PWD);

            stmt = connection.createStatement();

             

             

            //删除时如果是中文汉字要加单引号,如果是变量的话需要双引号单引号双引号

            String sql = "update student set teacher='"+teachername+"' where classname='"+classname+"'";

            // 执行SQL

            int count = stmt.executeUpdate(sql);

             

             

             

            // d.处理结果

            if (count > 0) { 

                System.out.println("操作成功！");

            }

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        } catch (SQLException e) {

            e.printStackTrace();

        } catch(Exception e) {

            e.printStackTrace();

        }

        finally {

            try {

                 if(stmt!=null) stmt.close();// 对象.方法

                 if(connection!=null)connection.close();

            }catch(SQLException e) {

                e.printStackTrace();

            }

        }

    }

 

 

}