laravel error when i try to update unique field

Question

when I just change the title field the content field will be an error because it only accepts unique value, if I don't use unique validation then there will be a possibility of paper with the same title, and I don't want it.

My method in controller:

 public function update(Paper $paper)
   {
       // validation
       $data = request()->validate([
           'title' => ['required', 'unique:papers'],
           'content' => ['required']
       ]);
       $data['slug'] = \Str::slug(request('title'));

       $paper->update($data);

       return redirect()->route('papers.show', $paper);
   }

Thanks for the help.

Answer 1

Welcome to StackOverflow!

This happens, because Laravel doesn't know what exact item you're trying to update. It simply checks if the given title exists already in the database. This is the case when you update your entity without changing it's title. Basically it is doing exactly what you asked it to do.

To prevent this, Laravel supports the option to exclude a given id from the rule. Instead of using unique:title , try using the following in your rule-set for an update. Be sure to import the Rule class:

'title' => [
    // ...
    Rule::unique('papers')->ignore($paper->id),
];

---

You can find more details about this procedure in the official documentation:

• https://laravel.com/docs/master/validation#rule-unique