Running and rolling back migrations in Laravel - Step-by-Step Execution

Concept Flow - Running and rolling back migrations

Start Migration Command

↓

Check Migration Files

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Apply Migration Changes to DB

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Update Migration Table

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Migration Complete

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Start Rollback Command

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Check Last Batch Migrations

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Revert Migration Changes in DB

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Update Migration Table

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Rollback Complete

This flow shows how Laravel applies migrations to update the database and how it rolls back the last batch of migrations to undo changes.

Execution Sample

Laravel

php artisan migrate
php artisan migrate:rollback

Run all pending migrations to update the database, then roll back the last batch of migrations to undo those changes.

Execution Table

Step	Command	Action	Database Change	Migration Table Update
1	php artisan migrate	Check for pending migrations	No change yet	No change
2	php artisan migrate	Apply migration: create users table	Users table created	Record migration batch 1
3	php artisan migrate	Apply migration: add email column	Email column added	Record migration batch 1
4	php artisan migrate	Migration complete	Database updated	Migration table updated with batch 1
5	php artisan migrate:rollback	Identify last batch migrations	No change yet	No change
6	php artisan migrate:rollback	Rollback migration: remove email column	Email column removed	Remove migration record from batch 1
7	php artisan migrate:rollback	Rollback migration: drop users table	Users table dropped	Remove migration record from batch 1
8	php artisan migrate:rollback	Rollback complete	Database reverted	Migration table updated
9	-	No more migrations to rollback	No change	No change

💡 Rollback stops after last batch is undone; no more migrations to rollback.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 6	After Step 7	Final
Database Schema	Empty	Users table created	Users table with email column	Users table created	Empty	Empty
Migration Table	Empty	Batch 1 recorded (users table)	Batch 1 recorded (users table + email column)	Batch 1 recorded (users table + email column)	Empty	Empty

Key Moments - 2 Insights

Why does rollback only undo the last batch of migrations?

Because Laravel groups migrations into batches and rollback reverses only the most recent batch, as shown in execution_table steps 5-8.

What happens if you run migrate when no migrations are pending?

No changes occur; the command checks and finds no new migrations, so the database and migration table stay the same (see execution_table step 1).

Visual Quiz - 3 Questions

Look at the execution table, what database change happens at step 3?

A Email column is added

B Users table is created

C Users table is dropped

D No change

💡 Hint

Check the 'Database Change' column at step 3 in the execution_table.

At which step does the rollback remove the users table?

A Step 6

B Step 7

C Step 8

D Step 9

💡 Hint

Look at the 'Action' and 'Database Change' columns for rollback steps in the execution_table.

If you run 'php artisan migrate' again after rollback, what happens?

A Nothing happens, no migrations pending

B Rollback runs automatically

C Migrations are applied again

D Database is reset

💡 Hint

Consider the variable_tracker showing database state after rollback and what migrate does with pending migrations.

Concept Snapshot

Laravel migrations update your database step-by-step.
Run 'php artisan migrate' to apply new migrations.
Run 'php artisan migrate:rollback' to undo the last batch.
Migrations are tracked in a special table.
Rollback only affects the most recent batch.
Always check migration status before running commands.

Full Transcript

This visual guide shows how Laravel runs and rolls back migrations. When you run 'php artisan migrate', Laravel looks for new migration files and applies them to update your database, like creating tables or adding columns. It records these changes in a migration table with batch numbers. When you run 'php artisan migrate:rollback', Laravel finds the last batch of migrations and reverses them in reverse order, updating the migration table accordingly. This process helps you manage database changes safely and step-by-step.