codeigniter update with where code example

Example 1: update query in codeigniter using where condition

public function update_row(){
		
		$update_rows = array('field-name' => 'field-data',);
		$this->db->where('id', 1 );
		$this->db->update('table-name', $update_rows);	

	}

Example 2: codeigniter select for update

$table = "my_table";
$id = 1;
$update = ["status"=>"working"];
//Edit just above /\ if you don't need extra "where" clause
$query = $this->db->select()
            ->from($table)
            ->where('id', $id)
            ->get_compiled_select();
$data = $this->db->query("$query FOR UPDATE")->row_array();
$this->db->where('id', $data['id'])->update($table,$update);