想要用java 连接数据库，需要在classpath中加上jdbc的jar包路径

在eclipse中，Project的properties里面的java build path里面添加引用

连接成功的一个小例子
数据库如下如

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代码

package query;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class query {

    public static void main(String[] args) {

        // 驱动程序名

        String driver = "com.mysql.jdbc.Driver";

        // URL指向要访问的数据库名9million

        String url = "jdbc:mysql://127.0.0.1:3306/9million";

        // MySQL配置时的用户名

        String user = "root";

        // MySQL配置时的密码

        String password = "";

        try {

            // 加载驱动程序

            Class.forName(driver);

            // 连续数据库

            Connection conn = DriverManager.getConnection(url, user, password);

            if (!conn.isClosed())

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

            // statement用来执行SQL语句

            Statement statement = conn.createStatement();

            // 要执行的SQL语句

            String sql = "select * from testdata";

            // 结果集

            ResultSet rs = statement.executeQuery(sql);

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

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

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

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

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

            String name = null;

            while (rs.next()) {

                // 选择sname这列数据

                name = rs.getString("name");

                // 首先使用ISO-8859-1字符集将name解码为字节序列并将结果存储新的字节数组中。

                // 然后使用GB2312字符集解码指定的字节数组

                name = new String(name.getBytes("ISO-8859-1"), "GB2312");

                // 输出结果

                System.out.println(rs.getString("id") + "\t" + name);

            }

            rs.close();

            conn.close();

        } catch (ClassNotFoundException e) {

            System.out.println("Sorry,can`t find the Driver!");

            e.printStackTrace();

        } catch (SQLException e) {

            e.printStackTrace();

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}