How to update the data being import from CSV file

I have create a php function to import the CSV/Excel file in to MYSQL database via CodeIgniter.

It will check whether there are duplicate rows of data in database,if yet,it will update the data, else it will insert the data my problem is when I update the CSV file and upload again,I get error of

Severity: Warning

Message: pathinfo() expects parameter 1 to be string, array given

Filename: core/Loader.php

Line Number: 759

this is my coding for import the CSV

class Upload_services extends CI_Model
{
    function __construct()
    {
        parent::__construct();
    }

    function upload_sampledata_csv()
    {
        if(isset($_POST['submit']))
        {
            $fp = fopen($_FILES['userfile']['tmp_name'],'r') or die("can't open file");
            while(($line = fgetcsv($fp, 10000, ",")) !== FALSE)
            {
                //check whether there are duplicate rows of data in database
                $prevQuery = array(
                    'articleno'           => $line[0],
                    'oldarticle'          => $line[1],
                    'product_description' => $line[2],
                    'pro_type'            => $line[3],   
                    'cust_group'          => $line[4] ,
                    'size'                => $line[5] ,
                    'colour'              => $line[6],
                    'output'              => $line[7],
                    'process_description' => $line[8],
                    'material_part'       => $line[9]

                );
                $where = array(
                    'articleno'           => $line[0],
                    'process_description' => $line[8],
                    'material_part'       => $line[9]
                    );
                $q = $this->db->select("*")
                    ->where($where)
                    ->from('sindi_productprocess_temp');
                $prevResult = $this->db->get();

                if($prevResult->num_rows > 0){
                    //update process data
                    $set =array('output'=>$line[7]);

                    $where = array(
                    'articleno'           => $line[0],                                  
                    'process_description' => $line[8],
                    'material_part'       => $line[9]
                    );

                $query = $this->db->get_where('sindi_productprocess_temp', array('output ='=>$line[7]))->result();

                }else{                
                    $data = array(
                        'articleno'           => $line[0],
                        'oldarticle'          => $line[1],
                        'product_description' => $line[2],
                        'pro_type'            => $line[3],   
                        'cust_group'          => $line[4] ,
                        'size'                => $line[5] ,
                        'colour'              => $line[6],
                        'output'              => $line[7],
                        'process_description' => $line[8],
                        'material_part'       => $line[9]
                    );

                    $data['crane_features']=$this->db->insert('sindi_productprocess_temp', $data);
                }
            }
            fclose($fp) or die("can't close file");
        }
    }
}

this is my CSV file that not yet being update CSV file

I want to change output for AB02-OKE-01-09-Y0-001 from 500 to 200 for material_part=Top PVC Sheet-Left,and 300 for Top PVC Sheet-Right

when i change the code as below,it working but instead of updated the existing data,it insert the duplicate data

            if($prevResult->num_rows > 0){
                //update process data

                $data = array(
                                'articleno'           => $line[0],
                                'oldarticle'          => $line[1],
                                'product_description' => $line[2],
                                'pro_type'            => $line[3],   
                                'cust_group'          => $line[4] ,
                                'size'                => $line[5] ,
                                'colour'              => $line[6],
                                'output'              => $line[7],
                                'process_description' => $line[8],
                                'material_part'       => $line[9]

                );

$set =array('output'=>$line[7]);

               $this->db->where = array(

                                'articleno'           => $line[0],
                                'oldarticle'          => $line[1],
                                'product_description' => $line[2],
                                'pro_type'            => $line[3],   
                                'cust_group'          => $line[4] ,
                                'size'                => $line[5] ,
                                'colour'              => $line[6],
                                'process_description' => $line[8],
                                'material_part'       => $line[9]
                );

            $this->db->update('sindi_productprocess_temp',$set);