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Building the database schema

Now that we have defined our models, we need to create the corresponding database 

schema. Thanks to Laravel's support for migrations and its powerful schema builder, 

you will not have to write any SQL code and you will also be able to keep track of 

any schema changes in a version control system. To create your first migration, open 

a new terminal window and enter the following command:

$ php artisan make:migration create_breeds_table --create=breeds

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This will create a new migration at 

database/migrations/

. If you open the newly 

created file, you will find some code that Laravel has generated for you. Migrations 

always have an 

up()

 and 

down()

 method that defines the schema changes when 

migrating up or down. Migrating up is modifying the database schema (that is, adding 

a table at a later date), whereas, migrating down is the process of undoing that schema 

change. By convention, the table and field names are written in snake_case. Also, the 

table names are written in plural form.

Our 

breeds

 table migration will look like this:

  public function up() {

    Schema::create('breeds', function($table) {

      $table->increments('id');

      $table->string('name');

    });

  }

  public function down() {

    Schema::drop('breeds');

  }

We can repeat the process to also create our 

cats

 table schema:

public function up() {

  Schema::create('cats', function($table) {

    $table->increments('id');

    $table->string('name');

    $table->date('date_of_birth');

    $table->integer('breed_id')->unsigned()->nullable();

    $table->foreign('breed_id')->references('id')->on('breeds');

  });

}

public function down() {

  Schema::drop('cats');

}

The 

date()

 and 

string()

 methods create fields with the corresponding types 

(in this case, 

DATE

 and 

VARCHAR

) in the database, 

increments()

 creates an auto-

incrementing 

INTEGER

 primary key, and 

timestamps()

 adds the 

created_at

 and 

updated_at

 

DATETIME

 fields that Eloquent expects, by default. The 

nullable()

 

method specifies that the column can have 

NULL

 values.

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Your First Application