Import relations error

I trying to import a json file with a belongsToMany relation. Here is a function that processes all relationship fields:

    protected $belongsToManyFields = ['categories', 'authors'];

    protected function processRelations($model, $data)
        foreach ($this->belongsToManyFields as $field) {
            if (isset($data[$field]) && !empty($data[$field])) {
                $ids = explode(',', $data[$field]);
                $relatedIds = array_map('trim', $ids);


When I don’t fill the “category” field in the json file or this field has only one value, e.g. 1 the import works fine, but when I have the values ​​separated by commas I get an error:

SQLSTATE[01000]: Warning: 1265 Data truncated for column 'categories_id' at row 1 (SQL: insert into `xyz_news_news_categories` (`categories_id`, `news_id`) values (1,2, 1))


json file:

        "name": "Test 1",
        "slug": "test1",
        "categories": "1,2"
        "name": "Test 2",
        "slug": "test2",
        "categories": "1"

The same error appears when importing a CSV file

After some time, I figured it out! :smile: