Mixing multidimensional array into one.

conentModel.php

public function getAllDataForACompany($company_reg_name){
		$data = [];
		$connection = new mysqli( self::DB_HOST, self::DB_USER, self::DB_PASSWORD, self::DB_NAME );
		if ( $connection ) {
			if ( $result = $connection->query( "SELECT * FROM APITester WHERE registerd_company_name = '$company_reg_name'", MYSQLI_USE_RESULT ) ) {
				$data['registerd_company_name'] = $company_reg_name;
				$registration_numbers = [];
				$catgeories = [];
				$company_classes = [];

				while ( $row = $result->fetch_assoc() ) {
					if(!in_array($data, $row)){
						$data['town'] = $row[ 'town' ];
					}
					if(!in_array($registration_numbers, $row)){
						array_push($registration_numbers, $row['registration_number']);
					}
					if(!in_array($company_classes, $row)){
						array_push($company_classes, $row['company_class']);
					}
					if(!in_array($catgeories, $row)){
						array_push($catgeories, $row['catgeory']);
					}
				}
				$data['registation_nembers'] =  array_unique($registration_numbers);
				$data['company_classes'] =  array_unique($company_classes);
				$data['catgeories'] =  array_unique($catgeories);
				
				return  $data;
		
			} else {
				return array( 'error' => 'nothing_to_see_here', 'rerun' => true, 'company_reg_name' => $company_reg_name );
			}
		} else {
			return array( 'error', 'no_possible_to_connect', 'conn' => false );
		}
	}