Builder class to have primaryKey and return primaryKey on insert

`CodeIgniter\Database\MySQLi\Builder` class seems to have no option setting primaryKey on run (primaryKey already exists in DB). This is the use case when we use isolated instance of a table using `$db->table('another_table')` where there seem no primaryKey property present as per DB schema or cannot either assign manually. Actually it won't return last_insert_id if primaryKey is missing as per my multiple attempts.

Am I missing something or is it worth requesting as a feature?


Attempts:
1. Tried setting primaryKey inside model and expecting some id to return after successful $tabl2->insert execution: 
$tabl2 = $this->db->table('table2');
$tabl2->primaryKey = 'term_id';
it does set primaryKey to the Builder object but doesn't seem to integrate it in property.

2. Tried getting insertId using $tabl2->insertID but its not defined after execution of the insert method.

Sorry, If I am not relevant to the forum.

Query Builder does not have/know primaryKey. It just build SQL queries.
You are confusing Query Builder and Model.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper