How to do this in Laravel, subquery where in

Question

Consider this code:

Products::whereIn('id', function($query){
    $query->select('paper_type_id')
    ->from(with(new ProductCategory)->getTable())
    ->whereIn('category_id', ['223', '15'])
    ->where('active', 1);
})->get();

Have a look at the advanced where clause documentation for Fluent. Here's an example of what you're trying to achieve:

DB::table('users')
    ->whereIn('id', function($query)
    {
        $query->select(DB::raw(1))
              ->from('orders')
              ->whereRaw('orders.user_id = users.id');
    })
    ->get();

This will produce:

select * from users where id in (
    select 1 from orders where orders.user_id = users.id
)

You can use variable by using keyword "use ($category_id)"

$category_id = array('223','15');
Products::whereIn('id', function($query) use ($category_id){
   $query->select('paper_type_id')
     ->from(with(new ProductCategory)->getTable())
     ->whereIn('category_id', $category_id )
     ->where('active', 1);
})->get();

You can use Eloquent in different queries and make things easier to understand and mantain:

$productCategory = ProductCategory::whereIn('category_id', ['223', '15'])
                   ->select('product_id'); //don't need ->get() or ->first()

and then we put all together:

Products::whereIn('id', $productCategory)
          ->where('active', 1)
          ->select('id', 'name', 'img', 'safe_name', 'sku', 'productstatusid')
          ->get();//runs all queries at once

This will generate the same query that you wrote in your question.

The following code worked for me:

$result=DB::table('tablename')
->whereIn('columnName',function ($query) {
                $query->select('columnName2')->from('tableName2')
                ->Where('columnCondition','=','valueRequired');

            })
->get();

The script is tested in Laravel 5.x and 6.x. The static closure can improve performance in some cases.

Product::select(['id', 'name', 'img', 'safe_name', 'sku', 'productstatusid'])
            ->whereIn('id', static function ($query) {
                $query->select(['product_id'])
                    ->from((new ProductCategory)->getTable())
                    ->whereIn('category_id', [15, 223]);
            })
            ->where('active', 1)
            ->get();

generates the SQL

SELECT `id`, `name`, `img`, `safe_name`, `sku`, `productstatusid` FROM `products` 
WHERE `id` IN (SELECT `product_id` FROM `product_category` WHERE 
`category_id` IN (?, ?)) AND `active` = ?