Why Supabase is the open-source Firebase alternative - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize a Supabase client with your project URL.

Supabase

const supabase = createClient('[1]', 'public-anonymous-key');

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

Ahttps://aws.amazon.com

Bhttps://firebase.google.com

Chttps://your-project.supabase.co

Dhttps://google.com

Attempts:

3 left

💡 Hint

Common Mistakes

Using Firebase or other cloud URLs instead of Supabase project URL.

You must use your Supabase project URL to connect the client properly.

2fill in blank

medium

Complete the code to sign up a user with email and password using Supabase.

Supabase

const { data, error } = await supabase.auth.[1]({ email, password });

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

Alogin

Bauthenticate

Cregister

DsignUp

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'login' or 'register' instead of 'signUp'.

The correct method to create a new user is signUp.

3fill in blank

hard

Fix the error in the code to fetch data from a Supabase table named 'profiles'.

Supabase

const { data, error } = await supabase.from('[1]').select('*');

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

Aprofiles

Baccounts

Cusers

Dauth

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect table names like 'users' or 'auth'.

The table name is 'profiles' to fetch user profile data.

4fill in blank

hard

Fill both blanks to insert a new row into the 'messages' table with Supabase.

Supabase

const { data, error } = await supabase.from('[1]').insert({ text: [2] });

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

Amessages

B'Hello, world!'

Cusers

D'Welcome!'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table names or missing quotes around text.

You insert into the 'messages' table and provide the text as a string.

5fill in blank

hard

Fill all three blanks to update a user's profile with Supabase.

Supabase

const { data, error } = await supabase.from('[1]').update({ [2]: [3] }).eq('id', userId);

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

Aprofiles

Busername

C'new_username'

Dusers

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table names or missing quotes around the new username.

Update the 'profiles' table, setting the 'username' field to a new string value.

Practice

1. What is one main reason Supabase is considered an alternative to Firebase?

easy

A. It is open-source and uses PostgreSQL as its database.

B. It only supports NoSQL databases.

C. It requires proprietary software licenses.

D. It does not provide real-time features.

Solution

1. Step 1: Understand Supabase's core features

   Supabase is known for being open-source and using PostgreSQL, a popular SQL database.

2. Step 2: Compare with Firebase

   Firebase is proprietary and uses NoSQL, while Supabase offers an open-source alternative with SQL.

3. Final Answer:

   It is open-source and uses PostgreSQL as its database. -> Option A

4. Quick Check:

   Open-source + PostgreSQL = C [OK]

Hint: Remember Supabase is open-source with SQL, unlike Firebase [OK]

Common Mistakes:

• Thinking Supabase only supports NoSQL
• Assuming Supabase is proprietary
• Believing Supabase lacks real-time features

2. Which of the following is the correct way to initialize a Supabase client in JavaScript?

easy

A. const supabase = createSupabase('url', 'key');

B. const supabase = createClient('url', 'key');

C. const supabase = supabase.create('url', 'key');

D. const supabase = supabaseClient('url', 'key');

Solution

1. Step 1: Recall Supabase client initialization syntax

   The official method is using createClient with URL and key as arguments.

2. Step 2: Check each option

   Only const supabase = createClient('url', 'key'); uses the correct function name and syntax.

3. Final Answer:

   const supabase = createClient('url', 'key'); -> Option B

4. Quick Check:

   createClient() is correct method [OK]

Hint: Look for createClient function with two string arguments [OK]

Common Mistakes:

• Using incorrect function names like supabaseClient or createSupabase
• Calling create as a method on supabase
• Mixing up argument order or missing quotes

3. Given this Supabase query in JavaScript:

const { data, error } = await supabase
  .from('users')
  .select('*')
  .eq('active', true);

What does data contain after execution?

medium

A. All users regardless of 'active' status.

B. An error object because the query is invalid.

C. All users where the 'active' field is true.

D. Only users where 'active' is false.

Solution

1. Step 1: Analyze the query filters

   The query selects all columns from 'users' where 'active' equals true.

2. Step 2: Understand the result

   The data variable holds the filtered list of users with active status true.

3. Final Answer:

   All users where the 'active' field is true. -> Option C

4. Quick Check:

   Filter .eq('active', true) returns active users [OK]

Hint: .eq('active', true) filters active users only [OK]

Common Mistakes:

• Assuming it returns all users without filtering
• Thinking it returns users with active false
• Believing the query causes an error

4. You wrote this Supabase query but get an error:

const { data, error } = await supabase
  .from('profiles')
  .select('id, name, email')
  .eq('verified', 'true');

What is the likely cause of the error?

medium

A. The 'verified' field is boolean but compared to string 'true'.

B. The table name 'profiles' is misspelled.

C. The select statement is missing parentheses.

D. Supabase does not support .eq() filters.

Solution

1. Step 1: Check data type mismatch in filter

   The query compares 'verified' boolean field to string 'true', causing type mismatch.

2. Step 2: Validate other parts

   Table name and select syntax are correct; .eq() is supported.

3. Final Answer:

   The 'verified' field is boolean but compared to string 'true'. -> Option A

4. Quick Check:

   Boolean compared to string causes error [OK]

Hint: Match filter value type to column type (boolean vs string) [OK]

Common Mistakes:

• Assuming .eq() is unsupported
• Thinking select needs parentheses
• Ignoring data type mismatch in filters

5. You want to avoid vendor lock-in by using Supabase instead of Firebase. Which feature of Supabase helps most with this?

hard

A. It stores data in a custom binary format.

B. It only works with proprietary cloud services.

C. It requires you to use Firebase SDKs.

D. It is open-source and uses a standard PostgreSQL database.

Solution

1. Step 1: Understand vendor lock-in

   Vendor lock-in happens when you depend on proprietary tech that is hard to move from.

2. Step 2: Identify Supabase's advantage

   Supabase is open-source and uses PostgreSQL, a widely supported standard database, easing migration.

3. Final Answer:

   It is open-source and uses a standard PostgreSQL database. -> Option D

4. Quick Check:

   Open-source + PostgreSQL = less lock-in [OK]

Hint: Open-source + standard DB = easy to switch later [OK]

Common Mistakes:

• Thinking Supabase requires Firebase SDKs
• Believing it uses proprietary cloud only
• Assuming data is stored in custom formats