Oct.12

Creating Migration file in Laravel Project

Migrations are like version control for your database, allowing your team to easily modify and share the application’s database schema. Migrations are typically paired with Laravel’s schema builder to easily build your application’s database schema. If you have ever had to tell a teammate to manually add a column to their local database schema, you’ve faced the problem that database migrations solve.

The Laravel Schema facade provides database agnostic support for creating and manipulating tables across all of Laravel’s supported database systems.

 

Generating Migrations

To create a migration, use the make:migration Artisan command:

 

php artisan make:migration create_users_table

 

The new migration will be placed in your database/migrations directory. Each migration file name contains a timestamp which allows Laravel to determine the order of the migrations.

The --table and --create options may also be used to indicate the name of the table and whether the migration will be creating a new table. These options simply pre-fill the generated migration stub file with the specified table:

 

php artisan make:migration create_users_table --create=users

php artisan make:migration add_votes_to_users_table --table=users

If you would like to specify a custom output path for the generated migration, you may use the --path option when executing the make:migration command. The given path should be relative to your application’s base path.

 

Migration Structure

A migration class contains two methods: up and down. The up method is used to add new tables, columns, or indexes to your database, while the down method should simply reverse the operations performed by the up method.

Within both of these methods you may use the Laravel schema builder to expressively create and modify tables. To learn about all of the methods available on the Schema builder, check out its documentation. For example, this migration example creates a flights table:

<?php

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

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

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

 

Column type Available method (function) for Database column type like Int, Varchar, long string, bool etc.

Running Migrations

To run all of your outstanding migrations, execute the migrate Artisan command:

php artisan migrate 

Forcing Migrations To Run In Production

Some migration operations are destructive, which means they may cause you to lose data. In order to protect you from running these commands against your production database, you will be prompted for confirmation before the commands are executed. To force the commands to run without a prompt, use the --force flag:

php artisan migrate --force

Rolling Back Migrations

To rollback the latest migration operation, you may use the rollback command. This command rolls back the last “batch” of migrations, which may include multiple migration files:

php artisan migrate:rollback

You may rollback a limited number of migrations by providing the step option to the rollback command. For example, the following command will rollback the last five migrations:

php artisan migrate:rollback --step=5
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