Prisma ORM setup in NextJS - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What happens when you run `prisma migrate dev` without a schema file?

You run the command prisma migrate dev in your Next.js project but you forgot to create or specify a schema.prisma file. What will happen?

A Prisma throws an error saying it cannot find the schema file.

B Prisma creates a default schema file automatically and runs migration.

C The command runs but skips migration silently.

D The command runs successfully and creates an empty migration.

💡 Hint

Think about what Prisma needs to know before it can create migrations.

Prisma requires a schema.prisma file to know your database models. Without it, the migrate command cannot proceed and throws an error.

📝 Syntax

intermediate

Which Prisma schema datasource block correctly connects to a PostgreSQL database?

Choose the correct datasource block for connecting Prisma to a PostgreSQL database.

A

datasource db {
  provider = "postgresql"
  url      = "DATABASE_URL"
}

B

datasource db {
  provider = "postgres"
  url      = env("DATABASE_URL")
}

C

datasource db {
  provider = "pg"
  url      = env("DATABASE_URL")
}

D

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

💡 Hint

The provider name must match Prisma's expected string exactly.

Prisma expects the provider to be exactly "postgresql" for PostgreSQL databases. The URL should be read from environment variables using env().

❓ state_output

advanced

What is the output of this Prisma client query in Next.js?

Given the following Prisma client code in a Next.js API route, what will be the output if the database has no users?

NextJS

import { PrismaClient } from '@prisma/client';
const prisma = new PrismaClient();

export default async function handler(req, res) {
  const users = await prisma.user.findMany();
  res.json({ count: users.length, users });
}

A {"count":0,"users":[]}

B {"count":0,"users":null}

C {"count":null,"users":null}

D An error is thrown because the user table is empty.

💡 Hint

Think about what findMany() returns when no records exist.

The findMany() method returns an empty array if no records are found, so users.length is 0 and users is an empty array.

🔧 Debug

advanced

Why does this Prisma client query throw a runtime error?

Consider this Prisma client query in a Next.js app:

const user = await prisma.user.findUnique({ where: { id: 123 } });
console.log(user.name);

Why might this code throw an error?

A Because the <code>id</code> field must be a string, not a number.

B Because <code>findUnique</code> returns null if no user with id 123 exists, so accessing <code>name</code> causes a TypeError.

C Because <code>findUnique</code> requires a second argument specifying fields to select.

D Because Prisma client methods must be called inside a React component.

💡 Hint

What happens if no record matches the query?

If no user with id 123 exists, findUnique returns null. Trying to access name on null causes a runtime TypeError.

🧠 Conceptual

expert

What is the main benefit of using Prisma's generated client in a Next.js app?

Why do developers prefer using Prisma's generated client instead of writing raw SQL queries in Next.js applications?

A It automatically scales the database server based on app traffic without configuration.

B It replaces the need for a database by storing data in memory.

C It provides type-safe database queries that catch errors during development and improve code reliability.

D It allows writing SQL queries directly inside React components without any setup.

💡 Hint

Think about how Prisma helps with code safety and developer experience.

Prisma generates a client with types based on your schema, so you get autocomplete and error checking before running your app, making database access safer and easier.