PHPExcel is a PHP library to handle both read/write from/to an excel file. Below is a short tutorial to cover reading data from an excel file.

$filename = 'your_file.xls';

require_once 'PHPExcel/Classes/PHPExcel.php';
	
// Create new PHPExcel object
$objReader = PHPExcel_IOFactory::createReader('Excel2007');
$objPHPExcel = $objReader->load($filename);

foreach ($objPHPExcel->getWorksheetIterator() as $worksheet) {
		
  $sheet_name = $worksheet->getTitle();

  foreach ($worksheet->getRowIterator() as $row) {
    $cellIterator = $row->getCellIterator();
    $cellIterator->setIterateOnlyExistingCells(false); // Loop all cells, even if empty
    foreach ($cellIterator as $cell) {
      if (!is_null($cell)) {
        $cell_coord = $cell->getCoordinate();
        $cell_val = $cell->getCalculatedValue();
        if (preg_match('/^([a-zA-Z]+)([0-9]+)$/', $cell_coord, $matches)){
          $col = $matches[1];
          $row = (int) $matches[2];
          do_something_with_this_cell($sheet_name, $col, $row, $cell_val);
        }
      }
    }
  }

}		

For do_something_with_this_cell($sheet_name, $col, $row, $cell_val), you can either store the value into DB for later analysis, or look up a mapping array and determine what that cell carries.

Sometimes you may need to deal with cells that carry dates. If you simply make the getCalculatedValue() call you will get some strange integer back but not the actual date string. The reason for that is, the date object in excel is actually masked by a date formatter. In order to get the desired date string, do the following:

foreach ($cellIterator as $cell) {
  if (!is_null($cell)) {
    $cell_coord = $cell->getCoordinate();
    $cell_val = $cell->getCalculatedValue();
    if (preg_match('/^([a-zA-Z]+)([0-9]+)$/', $cell_coord, $matches)){
      $col = $matches[1];
      $row = (int) $matches[2];

      // check for date object
      if(PHPExcel_Shared_Date::isDateTime($cell)){
        $cell_val = PHPExcel_Style_NumberFormat::toFormattedString($cell_val, "YYYY-MM-DD");
      }

      do_something_with_this_cell($sheet_name, $col, $row, $cell_val);
    }
  }
}