Seeding

Populating the database with fake data, now done appropriately.

Let's then seed the database, now using a script, as it is the correct approach.

To perform seeding with Prisma, we should create the seed file inside the prisma folder. In it, we'll instantiate a PrismaClient.

const prisma = new PrismaClient();

The PrismaService is not used here as it belongs to the context of Nest.

The seeding will be performed inside a transaction. So, let's create the seed() function, responsible for executing it. Just like in the other case, we should be aware of problems that may occur. Finally, invoke it afterwards.

const seed = async () => {
  try {
    await prisma.$transaction(async (tx: Prisma.TransactionClient) => {
      // seed goes here
    });

    await prisma.$disconnect();
  } catch (error) {
    console.error(error);
    await prisma.$disconnect();
    process.exit(1);
  }
};

seed();

Note that the $transaction() receives a parameter. It is a TransactionClient, which is a specific PrismaClient appropriate for transactions.

And now the actual seed. Just put it in place of the comment. Note that the orderItems and payment receive the appropriate Prisma type.

await tx.order.deleteMany();
await tx.user.deleteMany();
await tx.product.deleteMany();
await tx.category.deleteMany();

const cat1 = await tx.category.create({
  data: { name: 'Electronics' },
});
const cat2 = await tx.category.create({
  data: { name: 'Books' },
});
const cat3 = await tx.category.create({
  data: { name: 'Computers' },
});
const cat4 = await tx.category.create({
  data: { name: 'Games' },
});

const p1 = await tx.product.create({
  data: {
    name: 'Book of Cain',
    description: 'The writings of an elderly scholar about this perilous world.',
    price: 102.5,
    categories: { connect: [{ id: cat2.id }] },
  },
});
const p2 = await tx.product.create({
  data: {
    name: 'Smart TV',
    price: 2350,
    categories: { connect: [{ id: cat1.id }, { id: cat3.id }] },
  },
});
const p3 = await tx.product.create({
  data: {
    name: 'Macbook Pro',
    price: 1200,
    categories: { connect: [{ id: cat3.id }] },
  },
});
const p4 = await tx.product.create({
  data: {
    name: 'Gaming PC',
    description: 'Latest generation hardware for the best experience.',
    price: 2000,
    categories: { connect: [{ id: cat3.id }] },
  },
});
const p5 = await tx.product.create({
  data: {
    name: 'Game Mechanics: Advanced Game Design',
    description: 'Learn how to craft well-designed game mechanics.',
    price: 149.9,
    categories: { connect: [{ id: cat2.id }] },
  },
});
const p6 = await tx.product.create({
  data: {
    name: 'Warcraft III: Reign of Chaos',
    description: 'A true classic in the RTS genre.',
    price: 25.99,
    categories: { connect: [{ id: cat4.id }] },
  },
});

const u1 = await tx.user.create({
  data: {
    name: 'Pedro Faria',
    email: '[e-mail]',
    phone: '988888888',
    password: '123456',
  },
});
const u2 = await tx.user.create({
  data: {
    name: 'Chris Metzen',
    email: '[e-mail]',
    phone: '977777777',
    password: '654321',
  },
});

const oi1: Prisma.OrderItemCreateManyOrderInput = {
  productId: p1.id,
  quantity: 2,
  price: p1.price,
};
const oi2: Prisma.OrderItemCreateManyOrderInput = {
  productId: p3.id,
  quantity: 1,
  price: p3.price,
};
const oi3: Prisma.OrderItemCreateManyOrderInput = {
  productId: p3.id,
  quantity: 2,
  price: p3.price,
};
const oi4: Prisma.OrderItemCreateManyOrderInput = {
  productId: p5.id,
  quantity: 2,
  price: p5.price,
};

const pay1: Prisma.PaymentCreateWithoutOrderInput = {};

const o1 = await tx.order.create({
  data: {
    customer: { connect: { id: u1.id } },
    items: { create: [oi1, oi2] },
    status: OrderStatus.AWAITING_SHIPMENT,
    payment: { create: pay1 },
  },
});
const o2 = await tx.order.create({
  data: {
    customer: { connect: { id: u2.id } },
    items: { create: [oi3] },
    status: OrderStatus.AWAITING_PAYMENT,
  },
});
const o3 = await tx.order.create({
  data: {
    customer: { connect: { id: u1.id } },
    items: { create: [oi4] },
    status: OrderStatus.AWAITING_PAYMENT,
  },
});

What remains is simply to run the seed

yarn prisma:seed

And we may then see the result with Prisma Studio, which is a very clean tool for seeing and manipulating the database.

yarn prisma:studio

Commit - Seeding