Laravel Database Migrations: A Step-by-Step Guide

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Laravel Database Migrations: A Step-by-Step Guide

Introduction

Database migrations in Laravel provide a structured way to define and modify your database schema using PHP code instead of raw SQL. This feature makes database versioning, collaboration, and deployment more seamless and manageable.

By the end of this guide, you’ll understand how to create, modify, rollback, and seed migrations in Laravel efficiently.

What Are Migrations in Laravel?

Migrations act as version control for your database, allowing teams to work together without conflicts. Instead of manually editing tables, you write migration files that define schema changes, making it easier to track modifications over time.

Benefits of using migrations:

  • Consistency: Ensures that every developer’s database structure is the same.
  • Automation: Helps automate schema changes during deployment.
  • Rollback Support: Easily revert schema changes if needed.

Setting Up Migrations in Laravel

To use migrations, ensure you have Laravel installed and configured with a database connection in .env:

DB_CONNECTION=mysql  
DB_HOST=127.0.0.1  
DB_PORT=3306  
DB_DATABASE=laravel_db  
DB_USERNAME=root  
DB_PASSWORD=

Run the migration command to verify everything is working:

php artisan migrate

If successful, Laravel will create default tables like migrations, users, password_resets, etc.

Creating a New Migration

To create a new migration, use the Artisan command:

php artisan make:migration create_posts_table

This generates a new migration file inside the database/migrations/ directory. The file name follows the format:

YYYY_MM_DD_HHMMSS_create_posts_table.php

Inside the migration file, you’ll find two methods:

public function up()  
{  
    Schema::create('posts', function (Blueprint $table) {  
        $table->id();  
        $table->string('title');  
        $table->text('content');  
        $table->timestamps();  
    });  
}  

public function down()  
{  
    Schema::dropIfExists('posts');  
}
  • The up() method defines the schema for creating the posts table.
  • The down() method ensures that running php artisan migrate:rollback will drop the table.

Run the migration using:

php artisan migrate

This will create the posts table in your database.

Modifying an Existing Table

To alter an existing table, generate a new migration:

php artisan make:migration add_status_to_posts_table --table=posts

Modify the migration file to add a status column:

public function up()  
{  
    Schema::table('posts', function (Blueprint $table) {  
        $table->string('status')->default('draft');  
    });  
}  

public function down()  
{  
    Schema::table('posts', function (Blueprint $table) {  
        $table->dropColumn('status');  
    });  
}

Run the migration:

php artisan migrate

Now the posts table will include a status column with a default value of 'draft'.

Rolling Back Migrations

If you need to undo the last migration:

php artisan migrate:rollback

To rollback all migrations:

php artisan migrate:reset

To rollback and re-run migrations:

php artisan migrate:refresh

Seeding Data After Migrations

To populate tables with sample data, use Laravel Seeders. First, create a seeder:

php artisan make:seeder PostSeeder

Edit database/seeders/PostSeeder.php:

use Illuminate\Database\Seeder;
use Illuminate\Support\Facades\DB;

class PostSeeder extends Seeder  
{  
    public function run()  
    {  
        DB::table('posts')->insert([  
            'title' => 'First Post',  
            'content' => 'This is the first post.',  
            'status' => 'published',  
            'created_at' => now(),  
            'updated_at' => now(),  
        ]);  
    }  
}

Run the seeder:

php artisan db:seed --class=PostSeeder

To seed all available seeders, run:

php artisan db:seed

Migration Best Practices

1. Use Meaningful Migration Names

Instead of php artisan make:migration add_column, use php artisan make:migration add_status_to_posts_table --table=posts for clarity.

2. Always Define a down() Method

This ensures safe rollbacks in case of issues.

3. Avoid Directly Modifying the Database

Rely on migrations instead of altering tables manually via SQL.

4. Run Migrations in Production Cautiously

Use php artisan migrate --pretend to preview changes before execution.

5. Keep Migrations Organized

Delete old migrations once they become redundant after a schema update.

Conclusion

Laravel migrations streamline database management by offering a structured approach to schema modifications. Whether creating new tables, modifying columns, or rolling back changes, migrations keep database changes consistent and version-controlled.

By following best practices and leveraging migrations effectively, you can maintain a scalable and well-organized database structure in your Laravel projects. 🚀

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