fungsi edit data tidak berfungsi, ketika digunakan jadinya tambah data

saya berkendala ketika edit data tidak bisa. responnya jadi tambah data baru.

berikut syntaxnya :

<a href="<?php echo site_url('metadata/edit/'.$d['id']); ?>" class="btn btn-success btn-info"><i class="fa fa-edit"></i> Edit</a>

controllers :

function edit($id=0) {
		if ($id < 1) {
			$datanya = array(
				"id"=>$id,
				"indikator"=>"",
				"definisi"=>"",
				"rumus"=>"",
				"interpretasi"=>"",
				"penanggung_jawab"=>"",
				"keterangan"=>"",
				"required"=>"required"
			);
		} else {
			$this->db->where("id", $id);
			$datanya = $this->db->get("metadata")->row_array();
			$datanya['required'] = "";
		}

		$d['url'] = $this->url;
		$d['data'] = $datanya;
		$d['p'] = "form";
		$d['title'] = "Metadata";
		$d['menu_aktif'] = 5;
		$d['bredkum'] = bredkum(array("metadata"=>$d['title']), "metadata");

		$this->load->view('template', $d);
	}

views :

<li>
                    <a href="<?php echo site_url('metadata'); ?>">
                      <span class="sub-item">Metadata</span>
                    </a>
                  </li>

terimakasih