最简单的JAVA连接数据库

摘要：最基础的东西都不记得了，蛋疼。数据库连接成功语句执行成功语句执行成功没有找到数据库驱动连接数据库服务器失败

最基础的东西都不记得了，蛋疼。

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DB {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/test";
        String user = "root";
        String passwd = "123456";
        String sql1 = "SELECT * FROM score";
        String sql2 = "INSERT INTO score VALUES(25,905,"ENGLISH",84);";
        String sql3 = "UPDATE score SET grade=80 WHERE id=25";
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(url, user, passwd);
            System.out.println("数据库连接成功！");
            Statement stat = con.createStatement();
            ResultSet rs = stat.executeQuery(sql1);
            while (rs.next()) {
                int id = rs.getInt("id");
                int stu_id = rs.getInt("stu_id");
                String course = rs.getString("c_name");
                int grade = rs.getInt("grade");
                System.out.println(id + " " + stu_id + " " + course + " "
                        + grade);
            }
            int i = stat.executeUpdate(sql2);
            if (i != 0) {
                System.out.println("INSERT语句执行成功!");
            }
            int j = stat.executeUpdate(sql3);
            if (j != 0) {
                System.out.println("UPDATE语句执行成功!");
            }
            if (rs != null) {
                rs.close();
                rs = null;
            }
            if (stat != null) {
                stat.close();
                stat = null;
            }
            if (con != null) {
                con.close();
                con = null;
            }
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            System.out.println("没有找到数据库驱动！");
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            System.out.println("连接数据库服务器失败！");
        }
    }
}