What you are using is not Eloquent, but raw database queries.
RAW queries:
$table = 'your_table';
$columns = DB::select("SHOW COLUMNS FROM ". $table);
Question
How would I get inside of a custom model the columns for a specific MySQL table using Eloquent in Laravel
I was trying DB::query("SHOW COLUMNS FROM " . $table)
but without any success
Solution
What you are using is not Eloquent, but raw database queries.
RAW queries:
$table = 'your_table';
$columns = DB::select("SHOW COLUMNS FROM ". $table);
OTHER TIPS
There's no Eloquent function for this as it is considered out of its scope. I'd just do the following:
DB::select('show columns from '.(new MyModel)->getTable());