1. github创建项目仓库
2. 创建Vercel账号
3. 选择hobby
4. 连接github仓库
5. install - deploy
6. 创建postgres数据库（等待deploy完成）
   • Continue to Dashboard
   • Storage（头部nav哪里）
   • create Postgres
   • connect
   • 连接完后，切换到.env.local（Quickstart那里）
   • Copy Snippet
7. 项目根目录新增.env文件，把复制的东西，粘贴进去
8. .gitignore 新增.env，避免暴露数据库密钥
9. npm i @vercel/postgres
10. 创建文件
    • your project root/src/app/seed/route.ts
    • your project root/src/lib/placeholder-data.ts
11. 查看route.ts说明，安装依赖，打开sql语句的注释
12. 访问http://localhost:3000/seed
13. 浏览器显示{"message":"Database seeded successfully"}，数据库数据写入成功

/seed/route.ts

// todo npm install bcrypt || npm install bcryptjs
import bcrypt from 'bcrypt';
// import bcrypt from 'bcryptjs';

import { db } from '@vercel/postgres';
import { invoices, customers, revenue, users } from "@/lib/placeholder-data"

const client = await db.connect();

async function seedUsers() {
  await client.sql`CREATE EXTENSION IF NOT EXISTS "uuid-ossp"`;
  await client.sql`
    CREATE TABLE IF NOT EXISTS users (
      id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
      name VARCHAR(255) NOT NULL,
      email TEXT NOT NULL UNIQUE,
      password TEXT NOT NULL
    );
  `;

  const insertedUsers = await Promise.all(
    users.map(async (user) => {
      const hashedPassword = await bcrypt.hash(user.password, 10);
      return client.sql`
        INSERT INTO users (id, name, email, password)
        VALUES (${user.id}, ${user.name}, ${user.email}, ${hashedPassword})
        ON CONFLICT (id) DO NOTHING;
      `;
    }),
  );

  return insertedUsers;
}

async function seedInvoices() {
  await client.sql`CREATE EXTENSION IF NOT EXISTS "uuid-ossp"`;

  await client.sql`
    CREATE TABLE IF NOT EXISTS invoices (
      id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
      customer_id UUID NOT NULL,
      amount INT NOT NULL,
      status VARCHAR(255) NOT NULL,
      date DATE NOT NULL
    );
  `;

  const insertedInvoices = await Promise.all(
    invoices.map(
      (invoice) => client.sql`
        INSERT INTO invoices (customer_id, amount, status, date)
        VALUES (${invoice.customer_id}, ${invoice.amount}, ${invoice.status}, ${invoice.date})
        ON CONFLICT (id) DO NOTHING;
      `,
    ),
  );

  return insertedInvoices;
}

async function seedCustomers() {
  await client.sql`CREATE EXTENSION IF NOT EXISTS "uuid-ossp"`;

  await client.sql`
    CREATE TABLE IF NOT EXISTS customers (
      id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
      name VARCHAR(255) NOT NULL,
      email VARCHAR(255) NOT NULL,
      image_url VARCHAR(255) NOT NULL
    );
  `;

  const insertedCustomers = await Promise.all(
    customers.map(
      (customer) => client.sql`
        INSERT INTO customers (id, name, email, image_url)
        VALUES (${customer.id}, ${customer.name}, ${customer.email}, ${customer.image_url})
        ON CONFLICT (id) DO NOTHING;
      `,
    ),
  );

  return insertedCustomers;
}

async function seedRevenue() {
  await client.sql`
    CREATE TABLE IF NOT EXISTS revenue (
      month VARCHAR(4) NOT NULL UNIQUE,
      revenue INT NOT NULL
    );
  `;

  const insertedRevenue = await Promise.all(
    revenue.map(
      (rev) => client.sql`
        INSERT INTO revenue (month, revenue)
        VALUES (${rev.month}, ${rev.revenue})
        ON CONFLICT (month) DO NOTHING;
      `,
    ),
  );

  return insertedRevenue;
}

export async function GET() {
    return Response.json({
        message:
            'Uncomment this file and remove this line. You can delete this file when you are finished.',
    });

    try {
      await client.sql`BEGIN`;
      await seedUsers();
      await seedCustomers();
      await seedInvoices();
      await seedRevenue();
      await client.sql`COMMIT`;

      return Response.json({ message: 'Database seeded successfully' });
    } catch (error) {
      await client.sql`ROLLBACK`;
      return Response.json({ error }, { status: 500 });
    }
}

/lib/placeholder-data.ts

// This file contains placeholder data that you'll be replacing with real data in the Data Fetching chapter:
// https://nextjs.org/learn/dashboard-app/fetching-data
const users = [
    {
        id: '410544b2-4001-4271-9855-fec4b6a6442a',
        name: 'User',
        email: 'user@nextmail.com',
        password: '123456',
    },
];

const customers = [
    {
        id: 'd6e15727-9fe1-4961-8c5b-ea44a9bd81aa',
        name: 'Evil Rabbit',
        email: 'evil@rabbit.com',
        image_url: '/customers/evil-rabbit.png',
    }
];

const invoices = [
    {
        customer_id: customers[0].id,
        amount: 15795,
        status: 'pending',
        date: '2022-12-06',
    }
];

const revenue = [
    { month: 'Jan', revenue: 2000 }
];

export { users, customers, invoices, revenue };