使用MySQL数据库，建立一个模拟商店的数据库，数据库名为shop 在数据库中创建商品表goods，表结构如下： number（文本），name（文本），madeTime（日期），price（数字，双精度） 其中number为主键，表示商品编号。 往数据表随机写入30-50条数据。 编写程序，先查询出goods表中的数据，然后随机获取其中的10条记录，并计算出这10条记录price字段值的平均值，即平均价格，在控制台打印出10条记录和平均价格

以下是使用Java编写的示例代码来创建数据库和表，插入随机数据，并执行查询和计算平均价格的操作：

import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class ShopDatabase {
    private static final String URL = "jdbc:mysql://localhost:3306/shop";
    private static final String USERNAME = "your_username";
    private static final String PASSWORD = "your_password";

    public static void main(String[] args) {
        try {
            // 连接数据库
            Connection connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);

            // 创建商品表
            createGoodsTable(connection);

            // 插入随机数据
            insertRandomData(connection);

            // 查询商品表中的数据
            List<Goods> goodsList = queryGoodsTable(connection);

            // 随机获取10条记录并计算平均价格
            List<Goods> randomGoodsList = getRandomGoods(goodsList, 10);
            double averagePrice = calculateAveragePrice(randomGoodsList);

            // 打印10条记录和平均价格
            System.out.println("随机获取的10条记录：");
            for (Goods goods : randomGoodsList) {
                System.out.println(goods);
            }
            System.out.println("平均价格：" + averagePrice);

            // 关闭数据库连接
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private static void createGoodsTable(Connection connection) throws SQLException {
        String createTableQuery = "CREATE TABLE IF NOT EXISTS goods (" +
                "number VARCHAR(255) PRIMARY KEY," +
                "name VARCHAR(255)," +
                "madeTime DATE," +
                "price DOUBLE)";
        Statement statement = connection.createStatement();
        statement.execute(createTableQuery);
        statement.close();
    }

    private static void insertRandomData(Connection connection) throws SQLException {
        String insertQuery = "INSERT INTO goods (number, name, madeTime, price) VALUES (?, ?, ?, ?)";
        PreparedStatement statement = connection.prepareStatement(insertQuery);

        Random random = new Random();

        int numOfData = random.nextInt(21) + 30; // 生成30-50之间的随机数

        for (int i = 1; i <= numOfData; i++) {
            statement.setString(1, "G" + i);
            statement.setString(2, "商品" + i);
            statement.setDate(3, new Date(System.currentTimeMillis()));
            statement.setDouble(4, random.nextDouble() * 100);

            statement.executeUpdate();
        }

        statement.close();
    }

    private static List<Goods> queryGoodsTable(Connection connection) throws SQLException {
        String query = "SELECT * FROM goods";
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery(query);

        List<Goods> goodsList = new ArrayList<>();

        while (resultSet.next()) {
            String number = resultSet.getString("number");
            String name = resultSet.getString("name");
            Date madeTime = resultSet.getDate("madeTime");
            double price = resultSet.getDouble("price");

            Goods goods = new Goods(number, name, madeTime, price);
            goodsList.add(goods);
        }

        resultSet.close();
        statement.close();

        return goodsList;
    }

    private static List<Goods> getRandomGoods(List<Goods> goodsList, int num) {
        List<Goods> randomGoodsList = new ArrayList<>();
        Random random = new Random();

        int size = goodsList.size();
        if (size <= num) {
            return goodsList;
        }

        for (int i = 0; i < num; i++) {
            int randomIndex = random.nextInt(size);
            randomGoodsList.add(goodsList.get(randomIndex));
        }

        return randomGoodsList;
    }

    private static double calculateAveragePrice(List<Goods> goodsList) {
        double sum = 0;

        for (Goods goods : goodsList) {
            sum += goods.getPrice();
        }

        return sum / goodsList.size();
    }
}

class Goods {
    private String number;
    private String name;
    private Date madeTime;
    private double price;

    public Goods(String number, String name, Date madeTime, double price) {
        this.number = number;
        this.name = name;
        this.madeTime = madeTime;
        this.price = price;
    }

    public String getNumber() {
        return number;
    }

    public String getName() {
        return name;
    }

    public Date getMadeTime() {
        return madeTime;
    }

    public double getPrice() {
        return price;
    }

    @Override
    public String toString() {
        return "商品编号：" + number + ", 商品名称：" + name + ", 生产日期：" + madeTime + ", 价格：" + price;
    }
}

请将`your_username`和`your_password`替换为您的MySQL用户名和密码。该代码首先创建一个名为`shop`的数据库，然后在该数据库中创建名为`goods`的商品表，并插入30-50条随机数据。接下来，它查询商品表中的数据，并随机选择10条记录。最后，它计算这10条记录的平均价格，并将10条记录和平均价格打印到控制台上。

请确保您已经正确安装了MySQL数据库，并将Java代码中的数据库连接参数替换为您自己的数据库连接参数。