ORM options (Prisma, Drizzle) in Deno - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import Prisma Client in a Deno project.

Deno

import { PrismaClient } from '[1]';
const prisma = new PrismaClient();

Drag options to blanks, or click blank then click option'

Adeno-prisma

Bdrizzle-orm

Cnpm:@prisma/client

Dprisma-client-deno

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'drizzle-orm' instead of 'npm:@prisma/client' for Prisma imports.

Trying to import Prisma Client from a non-existent package.

Prisma Client is imported from 'npm:@prisma/client' to interact with the database.

2fill in blank

medium

Complete the code to define a Drizzle ORM table schema for a 'users' table.

Deno

import { pgTable, serial, text } from 'npm:drizzle-orm/pg-core';

export const users = pgTable('users', {
  id: [1]('id').primaryKey(),
  name: text('name').notNull(),
});

Drag options to blanks, or click blank then click option'

Avarchar

Bserial

Cbigint

Dinteger

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'integer' without auto-increment for primary key.

Using 'varchar' which is for text, not IDs.

The 'serial' function defines an auto-incrementing integer primary key in Drizzle ORM.

3fill in blank

hard

Fix the error in the Prisma query to find a user by email.

Deno

const user = await prisma.user.findUnique({
  where: { email: [1] },
});

Drag options to blanks, or click blank then click option'

A'[e-mail]'

BuserEmail

Cemail

DemailAddress

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name without defining it.

Not quoting the email string value.

The 'where' clause requires the actual email string value, so it must be quoted.

4fill in blank

hard

Fill both blanks to create a Drizzle ORM insert query for a new user.

Deno

await db.insert([1]).values({ name: [2] });

Drag options to blanks, or click blank then click option'

Ausers

B'Alice'

Cuser

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'user' instead of 'users' for the table name.

Not quoting the name string.

The 'users' table is the target for insertion, and the name value must be a string.

5fill in blank

hard

Fill all three blanks to write a Prisma update query that sets a user's name by ID.

Deno

await prisma.user.update({
  where: { id: [1] },
  data: { name: [2] },
  select: { [3]: true }
});

Drag options to blanks, or click blank then click option'

A42

B'Bob'

Cname

Demail

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the name string.

Using a string for the ID.

Selecting a field not present in the data.

The 'id' is a number, the new name is a string, and selecting 'name' returns the updated name.

Practice

1. What is the main purpose of using an ORM like Prisma or Drizzle in a Deno project?

easy

A. To manage server configurations and deployments

B. To create user interfaces for web applications

C. To write low-level network protocols

D. To interact with databases using simple and safe code instead of raw SQL

Solution

1. Step 1: Understand what ORM stands for

   ORM means Object-Relational Mapping, which helps connect code with databases easily.

2. Step 2: Identify ORM's role in Deno projects

   ORMs like Prisma and Drizzle let you write code to manage database data without writing raw SQL queries.

3. Final Answer:

   To interact with databases using simple and safe code instead of raw SQL -> Option D

4. Quick Check:

   ORM = Simple database code [OK]

Hint: ORMs simplify database work by hiding raw SQL [OK]

Common Mistakes:

• Confusing ORM with UI libraries
• Thinking ORM manages server setup
• Assuming ORM handles network protocols

2. Which of the following is the correct way to import Prisma Client in a Deno project?

easy

A. import { PrismaClient } from "@prisma/client";

B. import PrismaClient from "prisma/client";

C. const PrismaClient = require("@prisma/client");

D. import prisma from "deno-prisma";

Solution

1. Step 1: Recall Prisma Client import syntax

   Prisma Client is imported using ES module syntax with curly braces from "@prisma/client".

2. Step 2: Check each option for correctness

   import { PrismaClient } from "@prisma/client"; uses correct ES import syntax. import PrismaClient from "prisma/client"; misses curly braces. const PrismaClient = require("@prisma/client"); uses CommonJS require which is not used in Deno. import prisma from "deno-prisma"; uses a wrong package name.

3. Final Answer:

   import { PrismaClient } from "@prisma/client"; -> Option A

4. Quick Check:

   Prisma import uses curly braces and correct package [OK]

Hint: Prisma uses named import from "@prisma/client" [OK]

Common Mistakes:

• Using require() instead of import
• Missing curly braces in import
• Wrong package names

3. Given this Drizzle code snippet in Deno, what will be the output if the database has two users named 'Alice' and 'Bob'?

const users = await db.select().from(usersTable);
console.log(users.map(u => u.name));

medium

A. [{name: "Alice"}, {name: "Bob"}]

B. undefined

C. ["Alice", "Bob"]

D. SyntaxError

Solution

1. Step 1: Understand the select query

   The code selects all rows from usersTable and stores them in users array.

2. Step 2: Map user objects to their names

   users.map(u => u.name) creates a new array with only the name values from each user object.

3. Final Answer:

   ["Alice", "Bob"] -> Option C

4. Quick Check:

   Mapping user objects to names returns array of names [OK]

Hint: Mapping extracts just the names from user objects [OK]

Common Mistakes:

• Expecting full objects instead of names array
• Confusing map output with original array
• Assuming syntax error due to async

4. You wrote this Prisma query in Deno but get an error: const users = await prisma.user.findMany(). What is the likely cause?

medium

A. You must import Drizzle instead of Prisma

B. You forgot to instantiate PrismaClient before using it

C. You need to use raw SQL instead of Prisma queries

D. The findMany method does not exist in Prisma

Solution

1. Step 1: Check PrismaClient usage

   Before calling prisma.user.findMany(), you must create an instance: const prisma = new PrismaClient();

2. Step 2: Understand error cause

   If prisma is not instantiated, calling findMany() causes an error because prisma is undefined.

3. Final Answer:

   You forgot to instantiate PrismaClient before using it -> Option B

4. Quick Check:

   Instantiate PrismaClient before queries [OK]

Hint: Always create PrismaClient instance before queries [OK]

Common Mistakes:

• Assuming findMany doesn't exist
• Trying raw SQL instead of ORM methods
• Mixing Prisma and Drizzle imports

5. You want to use Drizzle ORM in Deno to insert a new user only if the username is not empty and then fetch all users. Which code snippet correctly applies this logic?

hard

A. if (username) {
await db.insert(usersTable).values({ name: username });
}
const allUsers = await db.select().from(usersTable);

B. await db.insert(usersTable).values({ name: username });
if (username) {
const allUsers = await db.select().from(usersTable);
}

C. const allUsers = await db.select().from(usersTable);
if (username) {
await db.insert(usersTable).values({ name: username });
}

D. await db.insert(usersTable).values({ name: username });
const allUsers = await db.select().from(usersTable);

Solution

1. Step 1: Check condition before insert

   We must insert only if username is not empty, so the insert is inside the if (username) block.

2. Step 2: Fetch all users after conditional insert

   After the conditional insert, we fetch all users with db.select().from(usersTable) and store in allUsers.

3. Final Answer:

   if (username) { await db.insert(usersTable).values({ name: username }); } const allUsers = await db.select().from(usersTable); -> Option A

4. Quick Check:

   Insert only if username, then fetch all users [OK]

Hint: Put insert inside if, then select all users [OK]

Common Mistakes:

• Inserting without checking username
• Fetching users before insert
• Fetching users inside the if block