无法将数据插入编码器中的数据库

我有这个程序无法插入数据，但总是重定向到"else"并显示消息错误"数据单元ID Sudah Digunakan">

这是我的控制器

$fleet = $this->input->post('id_fleet');
            $unit_id = $this->input->post('unit_id');
            $records = array();
            for ($i=0; $i < count($unit_id) ; $i++) { 
                $records[] = array(
                    'id_fleet' => $fleet,
                    'unit_id' => $unit_id[$i]
                    );
            }
            $query = $this->database_three->query("select
                count(id_fleet_member) as jumlah from fleet_member 
                where id_fleet = '$fleet' AND unit_id = '$unit_id'
                group by fleet_member.id_fleet");
            $ans = $query->row();
            $check = $this->database_three->query("
                select fleet.fleet_status as status, fleet_member.unit_id as unit
                from fleet, fleet_member 
                where fleet_member.unit_id = '$unit_id' AND fleet.id_fleet = '$fleet'");
            $ans2 = $query->row();

            if ($ans->jumlah > 0)
            {
                $this->session->set_flashdata('message', generateErrorMessage('Data Fleet ID Sudah Digunakan'));
                redirect(site_url('fleet_member'));     
            }
            else
            {
                if (!($check == FALSE)) {
                    $this->session->set_flashdata('message', generateErrorMessage('Data Unit ID Sudah Digunakan'));
                    redirect(site_url('fleet_member')); 
                }
                else
                {
                    foreach ($records as $data) 
                    {
                         $query = "insert into fleet_member (id_fleet, unit_id) values ('".$data['id_fleet']."','".$data['unit_id']."')"; 
                         $this->database_three->query($query);
                    }
                    $this->session->set_flashdata('message', generateSuccessMessage('Data berhasil ditambah'));
                    redirect(site_url('fleet_member'));
                }
            }

当单元 ID 未在同一转义 ID 中使用时，该程序可以插入。

你能帮助解决这个程序中的插入数据吗？