Laravel Migration - A Complete Tutorial

Laravel Migration - A Complete Tutorial

Laravel Create Migration, Manage Columns, Creating Indexes, Managing Foreign Key Constraints.

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Shani Singh
·Jun 7, 2022·

2 min read

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Laravel migration is like a version management tool of DATABASE.

Laravel Migration

Let's understand this better.

After Installing Laravel, let's understand migration.

Create a migration and understand the structure

To generate a migration you need to run a command

php artisan make:migration create_contacts_table

this will generate a file in database\migrations folder.

The file consists of a new class extending the migration class of LARAVEL.

The new class consist of 2 major function up() & down(). The up() function holds all information about migrating the file.

public function up()
{
    Schema::create('contacts', function (Blueprint $table) 
    {
            $table->id();
            $table->string('name');
            $table->string('mobile_no');
            $table->boolean('status');
            $table->timestamps();
    });
}

whereas the down() function holds information about reversing the migration action.

public function down()
{
    Schema::dropIfExists('contacts');
}

Run & Rollback The Migration

To run a migration we need to use the command

php artisan migrate

For rolling back the latest migration we have a command

php artisan migrate:rollback

when we have to roll back to specific steps we can pass steps in the rollback command like

php artisan migrate:rollback --step=3

this will roll back the migration up to 3 steps starting from the latest.

Adding/Updating Columns in Table

We need to generate a migration file similar to what we have created while creating the migration to perform any task.

the only change will be there in the migration name, always try to write the migration name descriptive which helps LARAVEL to understand the table name in migrations. For e.g. Updating the column name we should run commands like

php artisan make:migration update_name_column_in_contacts_table

Read more at Laravel Doc

Column Modifiers

Column Modifiers are nothing but a predefined function available in LARAVEL Migration by using that you can make any column nullable, Set Column default and many more.

You can check the available Laravel Column Modifier.

Add/Rename/Remove Database Indexes

Laravel Migration supports a few types of INDEXES for e.g.

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

Schema::table('users', function (Blueprint $table) {
    $table->index('email');
});

For renaming a index you can use renameIndex() for e.g.

$table->renameIndex('email', 'mobile_no');

For dropping a index you can use dropIndex() for e.g.

$table->dropIndex('email');

Foreign Key Constraints

Laravel also provides support for creating foreign key constraints, which are used to force referential integrity at the database level.

$table->foreignId('user_id')
      ->constrained('users')
      ->cascadeOnUpdate()
      ->cascadeOnDelete();

The Complete Video Tutorial is below in the video.

If you face any issues while implementing, please comment your query.

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