在数据透视表中以eloquent保存数据

Question

I am trying to achieve a simple insert into a pivot table but I cannot understand the principle why it does not work.

I have a Languages table which contains an id, name and code populated with languages. And I have a users table populated with users. The middle table is users_languages which has the columns user_id and and language_id.

My request has something like this

{
   "languages": [1, 2] -> language ids
}

My languages method into the Users model looks like this:

public function language() : BelongsToMany
{
    return $this
        ->belongsToMany(Language::class, 'users_languages')
        ->withPivot('user_id', 'language_id');
}

I am trying to add the languages like this:

public function setLanguages(array $languages) : self
{
    $this->language()->delete();
    $this->language()->createMany($languages);

    return $this;
}

The result I get is actually the its trying to create a new entry into the Languages table instead of just making a connection between the user_id and language_id.

I was looking through the documentation and some articles how this works but I none of the solutions I found worked. I am using Lumen 5.5 for my project. Thank you in advance for your help!

Answer 1

Use attach():

public function setLanguages(array $languages) : self
{
    $this->language()->attach($languages);

    return $this;
}

Use sync() if you want to remove the existing pivot entries.

public function setLanguages(array $languages) : self
{
    $this->language()->sync($languages);

    return $this;
}