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PHP / Laravel VIII (Eloquent)

Relationship between tables


Create the father table
  • php artisan mak:mig create_migration_card_table --create=cards

Create the child table

  • php artisan mak:mig create_migration_card_table --create=notes

Relationship

Create the foreign key in the child table

  • $table->integer('card_id')->unsigned()->index(); 

Create the Model

  • php artisan make:model Note
  • php artisan make:model Card

Shortcut

In this way we can create the model and the migration at the same time
  • php artisan make:model <Class> -m

Refresh DB

  • php artisan migrate:refresh 

Using Eloquent

In the father class (Model) add a method to get the childs

  • public function notes(){
  •         
  •         return $this->hasMany( <Class>::class );
  •         
  •     }

In the child class (Model) add the next method to get the father

 public function card(){
     
        return $this->belongsTo(Card::class);
     
    }

With this method we can relate a child more easily in tinker as:


  • $card->notes()->save($note);



Using Tinker

Get in a variable the registers of a table
  • $card =  App\Card::first();
Get all the results and then get the first
  • $card->notes->first();
Get the first result
  • $card->notes()->first();
Display the SQL commands that internally use tinker

  • DB::listen( function($query) { var_dump($query->sql); }  ) ;
  • Use fresh() if the query has been done due to Tinker save the query
    • $card->fresh()->notes->first();




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