Laravel validate if an ID has an instance of the relation - laravel

Question

This if kind of a finicky problem, and the title may be a bit confusing, so I'll try and explain as best as I can.
Basically, I am creating a Recipe application, where users can create lists and add recipes to them.
I want the lists to only be able to have one instance of each recipe, so for example, if I add Recipe 10 to List number 1, I don't want the user to be able to add Recipe 10 any more to List 1.
Right now I've only used validation for checking if the meal_id (the id for the recipe) already exists in the recipes table, but with this I am only able to add each recipe to one list.
$this->validate($request, [
'name' => 'required',
'meal_id' => 'required|unique:recipes,meal_id',
'list_id' => 'required'
]);
My relations are simply that a Recipe hasOne RecipeList, and a RecipeList hasMany Recipes, but I'm fairly certain changing that up wont be the fix.
Recipe model
class Recipe extends Model
{
use HasFactory;
protected $fillable = [
'name',
'meal_id',
'list_id'
];
public function lists()
{
return $this->hasOne(RecipeList::class);
}
}
RecipeList model
class RecipeList extends Model
{
use HasFactory;
protected $fillable = [
'name',
'user_id'
];
public function user()
{
return $this->belongsTo(User::class);
}
public function recipes()
{
return $this->hasMany(Recipe::class);
}
}
Recipes table
public function up()
{
Schema::create('recipes', function (Blueprint $table) {
$table->id();
$table->string('name');
$table->string('meal_id');
$table->unsignedBigInteger('list_id');
$table->timestamps();
});
}
However maybe I need to set up some form of pivot table?
Does anyone have any ideas on some smart way of achieving what I want through the validation, or any other ideas?

Answer 1

You can use Rule and create a custom validation to add your conditions.
Here I assume your condition is to add a unique restriction on both list_id and meal_id
$this->validate($request, [
'name' => 'required',
'list_id' => 'required',
'meal_id' => [
required,
unique:recipes,meal_id,
\Illuminate\Validation\Rule::unique('recipes')->where(function($query) use ($request){
$query->where('list_id', $request->list_id)
->where('meal_id', $request->meal_id);
}),
],
]);

Answer 2

Use firstOrCreate(). Read more here: https://laravel.com/docs/8.x/eloquent#retrieving-or-creating-models
Example:
$recipeData = $request->validate([
'name' => 'required',
'meal_id' => 'required',
'list_id' => 'required'
]);
$recipe = Recipe::firstOrCreate($recipeData);
This will use your 3 fields, name, meal_id & list_id and will either select one or create it if it doesn't exist already.
Alternatively you can do a query to check if it exists. If you want to return an error/message to the user explaining that the new one is a duplicate.
$existingRecipe = Recipe::where([
'meal_id' => $recipeData['meal_id'],
'list_id' => $recipeData['list_id'],
'name' => $recipeData['name']])
->first();
if(!is_null($existingRecipe)) {
//return exists
}
Of course, using rules will be more efficient, depends on what you want your UI to express.
See BABAK ASHRAFI's answer