我想用codeigniter从Excel插入数据，但我发现有些困难。当我上传文件时，主键中有一些数据双。我尝试在用codeigniter上传之前先检查它

$cek=$this->m_admin->get_redudant($data['cells'][$i][2]);
if ($cek==0) {
    $this->m_admin->add($dataexcel);
    redirect('home','refresh');
}
else{
    echo "something wrong";
}

下面是上传文件的函数：

function do_upload(){
    $config['upload_path'] = './temp_upload/';
    $config['allowed_types'] = 'xls';           
    $this->load->library('upload', $config);                
    if ( ! $this->upload->do_upload())
    {
        $data = array('error' => $this->upload->display_errors());          
    }
    else
    {
        $data = array('error' => false);
        $upload_data = $this->upload->data();

        $this->load->library('excel_reader');
        $this->excel_reader->setOutputEncoding('CP1251');

        $file =  $upload_data['full_path'];
        $this->excel_reader->read($file);
        error_reporting(E_ALL ^ E_NOTICE);

        $data = $this->excel_reader->sheets[0] ;
        $dataexcel = Array();
        $i=0;
        for ($i = 1; $i <= $data['numRows']; $i++) {
                        if($data['cells'][$i][1] == '') break;
                        $dataexcel[$i-1]['nip'] = $data['cells'][$i][2];
                        $dataexcel[$i-1]['nama'] = $data['cells'][$i][1];
                        $dataexcel[$i-1]['nipbr'] = $data['cells'][$i][3];
                        $dataexcel[$i-1]['tempat'] = $data['cells'][$i][4];
                        $dataexcel[$i-1]['lahir'] = $data['cells'][$i][5];
                        $dataexcel[$i-1]['temp_kerja'] = $data['cells'][$i][6];
        }

        delete_files($upload_data['file_path']);            
        $cek=$this->m_admin->get_redudant($data['cells'][$i][2]);

        if ($cek==0) {
            $this->m_admin->add($dataexcel);
            redirect('home','refresh');
        }
        else{
            echo "something wrong";
        }    
    }

}

我想操作主键中的数据。如果数据存在，我将在id的末尾随机添加数据，如

else{
        $x = rand(1, 1000); 
        $dataexcel[$i-1]['nip'] = $data['cells'][$i][2]."$x";
}

但是不起作用，我该怎么办？