How to loop for searching id by row using php excel

I want to create an import from excel to database. But in one of the inputs are using <select> which has the value of an id. like this:

<select id="merchant" name="merchant">
                        <?php 
                            foreach($merchant as $opt_merchant){
                        ?>
                            <option value="<?= $opt_merchant['merchant_id'] ?>"><?= $opt_merchant['merchant_name'] ?></option>
                        <?php
                            }
                        ?>
</select>

How do I get the ID when the user only input the merchant_name in the excel?

my senior told me to get all the merchants first, then when it loops, just search for the object by name, then get the id. But I don’t know how to get each row of merchant_name and then search for their id.

the controller for the import:

public function import_retail_proses(){
    $this->load->library(array('excel','session'));
    if (isset($_FILES["fileExcel"]["name"])) {
        $path = $_FILES["fileExcel"]["tmp_name"];
        $object = PHPExcel_IOFactory::load($path);
        foreach($object->getWorksheetIterator() as $worksheet)
        {
            $highestRow     = $worksheet->getHighestRow();
            $highestColumn  = $worksheet->getHighestColumn();   
            $values         = [];
            for($row=2; $row<=$highestRow; $row++)
            {
                $pos_pelanggan_code = $worksheet->getCellByColumnAndRow(0, $row)->getValue();
                $pos_merchant       = $worksheet->getCellByColumnAndRow(1, $row)->getValue();
                $pos_name           = $worksheet->getCellByColumnAndRow(2, $row)->getValue();
                $pos_sales_name     = $worksheet->getCellByColumnAndRow(3, $row)->getValue();
                $pos_address        = $worksheet->getCellByColumnAndRow(4, $row)->getValue();
                $pos_email          = $worksheet->getCellByColumnAndRow(5, $row)->getValue();
                $pos_phone          = $worksheet->getCellByColumnAndRow(6, $row)->getValue();
                $pos_website            = $worksheet->getCellByColumnAndRow(7, $row)->getValue();
                $pos_npwp   = $worksheet->getCellByColumnAndRow(8, $row)->getValue();
                $pos_post_code = $worksheet->getCellByColumnAndRow(9, $row)->getValue();
                $pos_fax    = $worksheet->getCellByColumnAndRow(10, $row)->getValue();
                $pos_vip    = $worksheet->getCellByColumnAndRow(11, $row)->getValue();
                $values[]       = array(
                'kode_pelanggan' => $pos_pelanggan_code,
                'nama' => $pos_name,
                'vip' => 0,
                'tgl_daftar' => date('Y-m-d H:i:s'),
                'alamat' => $pos_address,
                'email' => $pos_email,
                'no_hp' => $pos_phone,
                'website' => $pos_website,
                'no_npwp' => $pos_npwp,
                'kode_pos' => $pos_post_code,
                'no_fax' => $pos_fax,
                'limit' => 0,
                'top' => 0,
                'merchant' => $pos_merchant,
                'jenis_pelanggan' => 0
                );
            }
        }
        $insert     = $this->db->insert_batch('pelanggan',$values);
        if( $insert ) {
            $this->session->set_flashdata('success','Import item');
            redirect($_SERVER['HTTP_REFERER']);
        }else{
            print_r('error ');die;
        }
    } else {
        echo "Tidak ada file yang masuk";die;
    }
}