Import from Excel to MYSQL is not working

Code:
//load library phpExcel

$this->load->library('PHPExcel'); 

  

// File Location

$inputFileName = './attach/flexi.xlsx';

  

//Load $inputFileName to a PHPExcel Object  

$inputFileType = 'Excel2007';

$objReader = new PHPExcel_Reader_Excel2007();

$objReader = PHPExcel_IOFactory::createReader($inputFileType);

$objPHPExcel = $objReader->load($inputFileName);

$objWorksheet = $objPHPExcel->setActiveSheetIndex(0);



for ($i=1; $i<=77; $i++){

 $category = $objWorksheet->getCellByColumnAndRow(0,$i)->getValue();

 $description = $objWorksheet->getCellByColumnAndRow(1,$i)->getValue();

 $transaction_date = $objWorksheet->getCellByColumnAndRow(2,$i)->getValue();

 $amount = $objWorksheet->getCellByColumnAndRow(3,$i)->getValue();

 $employee_id = $objWorksheet->getCellByColumnAndRow(4,$i)->getValue();   

   

 $data_flexi = array(

  'category'   => $category,

  'description'  => $description,

  'transaction_date'  => $transaction_date,

  'amount'   => $amount,

  'employee_id'  => $employee_id,

  'create_by'   => '2'

 );

}



$this->Flex_m->upload_flexi($data_flexi);

$this->load->view('flex/thanks');