为什么会出现数组到字符串转换错误？

Question

I have the following two SQL queries the first one looks up the partner_id in a table called orders , the second one changes the partner name using the partner_id but I get the error "array to string conversion".

How to set partner_id to be an integer?

$partner_id_ = DB::select('select partner_id from orders where id = ? ', [$id]);

DB::update('update partners set name = ? where id =?',[$partner,$partner_id_]);

Answer 1

$partner_id_ = DB::select('select partner_id from orders where id = ? ', [$id]);

Defines $partner_id_ as an array with 1 element of stdClass with single property partner_id .

If you are sure that you will always find at least one row there, change $partner_id_ to $partner_id_[0]->partner_id in the following line:

DB::update('update partners set name = ? where id =?',[$partner,$partner_id_[0]->partner_id]);