Learn Next Js guide, setting up your database

[KandyBobber]

I had an issue when I created tables in the database. I uncommented lines, deleted the line with text as instructed in the guide, then visited the localhost/seed URL and encountered an error: Error: [object Object]. I attached a photo of it. I fixed the issue by installing the pg library and rewriting methods to use the pg style. In my opinion, the guide itself is to blame for the problem because it doesn't provide instructions for using a local database. I was using PostgreSQL in a Docker container. Further, you can find the correct code.

Please don't forget run before using solve:

pnpm i pg

import bcrypt from 'bcrypt';
import { invoices, customers, revenue, users } from '../lib/placeholder-data';
import pg from 'pg';

const { Client } = pg;
const client = new Client({
    user: process.env.POSTGRES_USER,
    password: process.env.POSTGRES_PASSWORD,
    host: process.env.POSTGRES_HOST,
    port: process.env.POSTGRES_PORT,
    database: process.env.POSTGRES_DATABASE,
});
await client.connect();

async function seedUsers() {
    await client.query(`CREATE EXTENSION IF NOT EXISTS "uuid-ossp"`);
    await client.query(`
    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.query(
                `
        INSERT INTO users (id, name, email, password)
        VALUES ($1, $2, $3, $4)
        ON CONFLICT (id) DO NOTHING;
      `,
                [user.id, user.name, user.email, hashedPassword]
            );
        })
    );

    return insertedUsers;
}

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

    await client.query(`
    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.query(
                `
        INSERT INTO invoices (customer_id, amount, status, date)
        VALUES ($1, $2, $3, $4)
        ON CONFLICT (id) DO NOTHING;
      `,
                [invoice.customer_id, invoice.amount, invoice.status, invoice.date]
            )
        )
    );

    return insertedInvoices;
}

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

    await client.query(`
    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.query(
                `
        INSERT INTO customers (id, name, email, image_url)
        VALUES ($1, $2, $3, $4)
        ON CONFLICT (id) DO NOTHING;
      `,
                [customer.id, customer.name, customer.email, customer.image_url]
            )
        )
    );

    return insertedCustomers;
}

async function seedRevenue() {
    await client.query(`
    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.query(
                `
        INSERT INTO revenue (month, revenue)
        VALUES ($1, $2)
        ON CONFLICT (month) DO NOTHING;
      `,
                [rev.month, rev.revenue]
            )
        )
    );

    return insertedRevenue;
}

export async function GET() {
    try {
        await client.query(`BEGIN`);
        await seedUsers();
        await seedCustomers();
        await seedInvoices();
        await seedRevenue();
        await client.query(`COMMIT`);
        await client.end();
        return Response.json({ message: 'Database seeded successfully' });
    } catch (error) {
        await client.query(`ROLLBACK`);
        await client.end();
        return Response.json({ error }, { status: 500 });
    }
}