I’m not sure if my reply really address your question, so be patient if not!
use Cake\Datasource\ConnectionManager;
and then
$conn = ConnectionManager::get(‘default’);
$results = $conn->newQuery()
->select('abc')
->from('TSpec')
->where(['SC =' => '169/02'])
->execute()
->fetchAll('assoc');
or if you prefer:
$query = "select abc from TSpec where SC='169/02'";
$results = $this->conn->execute($query)->fetchAll('assoc');