eloquent - Laravel returning only single column -

in database have categories , sizes, have table match them called category_sizes looks like:

i want array size_id category_id = 4 did:

$catsizes = categorysize::where('category_id', 4)->value('size_id'); return($catsizes);

but returns 1 result only. how can array size_ids can use later in where_in statement.

i tried pluck gives 1 row.

$catsizes = categorysize::where('category_id', 4)->pluck('size_id'); dd($catsizes);

my categoysize model

<?php  namespace app;  use illuminate\database\eloquent\model;  class categorysize extends model {     protected $table = 'category_sizes'; }

try this:

db::table('category_sizes')->where('category_id', 4)->get('size_id');

or:

db::table('category_sizes')->select('size_id')->where('category_id', 4)->get();

Shell