Rolling back migrations in Supabase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to rollback the last migration in Supabase CLI.

Supabase

supabase migration [1]

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

Aapply

Bstatus

Ccreate

Drollback

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'apply' instead of 'rollback' will apply migrations instead of undoing them.

Using 'create' is for making new migrations, not rolling back.

The rollback command undoes the last applied migration in Supabase.

2fill in blank

medium

Complete the command to rollback migrations by specifying the number of steps.

Supabase

supabase migration rollback --steps [1]

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

Aall

B1

C0

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'all' is not valid for the steps option.

Using '0' means no rollback will happen.

Using --steps 1 rolls back the last migration step.

3fill in blank

hard

Fix the error in the command to rollback migrations by adding the missing flag.

Supabase

supabase migration rollback [1] 2

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

A--steps

B--number

C--migrate

D--count

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--count' or '--number' are not recognized flags for rollback steps.

Omitting the flag causes the command to fail.

The correct flag to specify how many migrations to rollback is --steps.

4fill in blank

hard

Fill both blanks to rollback migrations and confirm the action automatically.

Supabase

supabase migration rollback [1] 1 [2]

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

A--steps

B--force

C--confirm

D--dry-run

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--confirm' instead of '--force' does not skip prompts.

Using '--dry-run' only simulates rollback without applying it.

Use --steps to specify how many migrations to rollback and --force to skip confirmation prompts.

5fill in blank

hard

Fill all three blanks to rollback two migrations quietly and specify the project directory.

Supabase

supabase migration rollback [1] 2 [2] --project-dir [3]

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

A--steps

B--force

C./my-project

D--quiet

Attempts:

3 left

💡 Hint

Common Mistakes

Using '--quiet' instead of '--force' does not skip confirmation prompts.

Omitting the project directory causes the command to run in the current folder.

Use --steps to set rollback count, --force to skip confirmation, and --project-dir to specify the project folder path.

Practice

1. What does the command supabase db rollback do?

easy

A. It creates a new migration file.

B. It undoes the last applied database migration.

C. It applies all pending migrations to the database.

D. It deletes the entire database.

Solution

1. Step 1: Understand the purpose of rollback

   Rollback means undoing changes, so this command reverses migrations already applied.

2. Step 2: Identify the command effect

   supabase db rollback specifically undoes the last migration applied to the database.

3. Final Answer:

   It undoes the last applied database migration. -> Option B

4. Quick Check:

   Rollback = undo last migration [OK]

Hint: Rollback means undo last migration applied [OK]

Common Mistakes:

• Confusing rollback with applying migrations
• Thinking rollback creates new migrations
• Assuming rollback deletes the database

2. Which of the following is the correct syntax to rollback the last 3 migrations using Supabase CLI?

easy

A. supabase db rollback --steps 3

B. supabase db rollback -n 3

C. supabase rollback db 3

D. supabase db undo 3

Solution

1. Step 1: Recall the rollback command syntax

   The Supabase CLI uses --steps to specify how many migrations to rollback.

2. Step 2: Match the correct option

   supabase db rollback --steps 3 uses supabase db rollback --steps 3, which is the correct syntax.

3. Final Answer:

   supabase db rollback --steps 3 -> Option A

4. Quick Check:

   Use --steps to rollback multiple migrations [OK]

Hint: Use --steps to specify rollback count [OK]

Common Mistakes:

• Using incorrect flags like -n instead of --steps
• Wrong command order like 'rollback db'
• Using 'undo' instead of 'rollback'

3. Given the following commands run in order:
supabase db push
supabase db push
supabase db rollback --steps 1
What is the state of migrations after these commands?

medium

A. All migrations are rolled back except the last one.

B. No migrations are applied.

C. Both migrations are still applied.

D. Only the first migration is applied.

Solution

1. Step 1: Apply two migrations

   Running supabase db push twice applies two migrations in order.

2. Step 2: Rollback one migration

   The rollback with --steps 1 undoes the last applied migration, leaving the first migration applied.

3. Final Answer:

   Only the first migration is applied. -> Option D

4. Quick Check:

   Rollback 1 step removes last migration applied [OK]

Hint: Rollback with --steps 1 undoes last migration only [OK]

Common Mistakes:

• Assuming rollback removes all migrations
• Thinking rollback does not affect applied migrations
• Confusing push and rollback order

4. You run supabase db rollback --steps 2 but get an error saying no migrations to rollback. What is the most likely cause?

medium

A. There are fewer than 2 migrations applied to rollback.

B. The migrations folder is missing.

C. The database connection is not configured.

D. Rollback command requires a --force flag.

Solution

1. Step 1: Understand rollback error

   The error indicates no migrations to rollback, meaning none or fewer than requested are applied.

2. Step 2: Identify cause

   If fewer than 2 migrations are applied, trying to rollback 2 steps causes this error.

3. Final Answer:

   There are fewer than 2 migrations applied to rollback. -> Option A

4. Quick Check:

   Rollback steps > applied migrations causes error [OK]

Hint: Check applied migrations count before rollback steps [OK]

Common Mistakes:

• Assuming rollback always works without applied migrations
• Thinking rollback needs --force flag
• Ignoring database connection issues

5. You have applied 5 migrations but want to rollback only the 3rd migration without affecting others. Which approach is best?

hard

A. Delete the 3rd migration file and run supabase db push.

B. Use supabase db rollback --steps 3 to rollback only the 3rd migration.

C. Rollback all migrations from the 3rd onwards, then reapply the ones after it.

D. Directly edit the database to remove changes from the 3rd migration.

Solution

1. Step 1: Understand migration order

   Migrations apply in order; you cannot rollback a middle migration without undoing later ones first.

2. Step 2: Plan rollback and reapply

   Rollback migrations after the 3rd (steps 2), then rollback the 3rd, then reapply the later migrations.

3. Final Answer:

   Rollback all migrations from the 3rd onwards, then reapply the ones after it. -> Option C

4. Quick Check:

   Rollback middle migration requires undoing later ones first [OK]

Hint: Undo later migrations first, then rollback target migration [OK]

Common Mistakes:

• Trying to rollback a single middle migration directly
• Deleting migration files without rollback
• Editing database manually causing inconsistency