Question

如何修复此程序？

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

class MySqlData {
    public static void main(String args[]) throws Exception {
        DriverManager.registerDriver(new com.mysql.jdbcDriver());
        Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test/user=root&password=merimaa");
        Statement stmt = con.createStatement();
        ResultSet res=stmt.executeQuery("Select * from employee");
        while (res.next()) {
            System.out.println(res.getString("employee_name"));
        }
        con.close();
    }
}

Answer 1

正如其他人所说：

您的代码很好
您的错误与类路径问题有关
下载MySQL java库
http://dev.mysql.com/downloads/connector/j/5.0.html
阅读文档 http://dev.mysql.com/doc/refman/5.1/en/connector-j.html

Answer 2

将包含sql驱动程序的相应jar文件添加到类路径

Answer 3

首先你需要下载一个mysql驱动程序，然后设置一些与mysql连接的异常捕获器，或者抛出一些异常。

Answer 4

您需要下载MySQL连接器。

从这里下载：https://dev.mysql.com/downloads/connector/j/

并将其放在项目文件夹中

Answer 5

将Jar文件添加到WEB-INF / lib。

使用以下

<%@ page import="java.sql.*" %> 
<%@ page import="java.io.*" %> 


 try {
            String connectionURL = "jdbc:mysql://host/db";
            Connection connection = null; 
            Class.forName("com.mysql.jdbc.Driver").newInstance(); 
            connection = DriverManager.getConnection(connectionURL, "username", "password");
            if(!connection.isClosed())
                 out.println("Successfully connected to " + "MySQL server using TCP/IP...");
            connection.close();
        }catch(Exception ex){
            out.println("Unable to connect to database"+ex);
        }

https://stackoverflow.com/a/13506117/876739

如何修复ERROR PACKAGE com.mysql不存在

5 个答案: