Laravel Migration

Migrations are generally used to modify the database schema. Along with Laravel’s schema builder, it builds the application’s database schema. Designing tables not only become easy with the use of migrations, but the entire table can also be created.

Migrations are stored in : database/migrations

1. Generate Migration:
   Make:migration – This command is used to generate a migration

   php artisan make:migration sample_table

   This will generate a migration with the name SampleTable

   

2. Migration Structure
   It contains two methods: up and down.
   New columns, tables or indexes are added to the database using the up method.
   The operations performed by the up method are reversed by the down method.

   <?php
   
   use Illuminate\Support\Facades\Schema;
   use Illuminate\Database\Schema\Blueprint;
   use Illuminate\Database\Migrations\Migration;
   
   class SampleTable extends Migration
   {
       /**
        * Run the migrations.
        *
        * @return void
        */
       public function up()
       {
           //
       }
   
       /**
        * Reverse the migrations.
        *
        * @return void
        */
       public function down()
       {
           //
       }
   }
   

3. Running Migration
   php artisan migrate – this command is used to run the migration.
   This will create the migration and insert an entry into the migration table.

   

4. RollBack a Migration
   php artisan migrate:rollback – This command is used to rollback a migration

   

5. Drop All Tables & Migrate
   php artisan migrate:fresh – This command is used to drop all the tables in the database.

Tables

1. Create Table
   Create method is used to create a new database table on the Schema facade. It accepts two arguments.
   • The name of the table
   • Blueprint object – Used to define the new table:

     Schema::create(‘sample_table’, function (Blueprint $table) {
     $table->increments(‘id’);
     });

2. Rename a Table
   To rename an existing method use rename method

   Schema::rename($from, $to);

3. Drop a Table
   To drop the table use drop or dropIfExists method.

   	
       Schema::drop('sample_table');
       or
       Schema::dropIfExists('sample_table');
   

Run a specific migration
We will create sample_table with some columns:

<?php

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

class SampleTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
          Schema::create('sample_table', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
         Schema::dropIfExists('sample_table');
    }
}

To run only this migration we need to add the path of this migration in migrate command

php artisan migrate –path=/database/migrations/2019_04_08_121257_sample_table.php

With this, we can run a specific migration.

The table is created along with the fields.