Question

I’m having this problem when I tried to extract information from excel files. Here’s my situation, I have 34 Excel files which I received from my various users.

I’m using PHP version 5 to extract from the Excel files. My script will loop for every files, and looping again according to sheet name, and lastly looping again according to cell addresses.

The problem arised when the users had entered into a cell for e.g. =+A1 which means the users referencing the cell value to another cell due to it has the same value with cell A1.

When I checked in mysql (as I saved those for future use) I found from the record for a particular cell is identical with another record obtained from the same cell but in different excel file. What I meant is that, as my php script will loop from one file to another file, the first time PHPExcel read for e.g cell C3 which has some value USD3,000.00 the next files the PHPExcel may go to the same cell C3 but this time the C3 cell contain a formula that referencing to cell A1 (“=+A1” formula)which has value USD5,000.00.

PHP script suppose to record in mysql for USD5,000.00 but it didn’t. I suspect that the PHPExcel script did not clear the variable at first round. I’ve tried unset($objPHPExcel) and destroy the variable but it still happening.

My coding is simple as follows:

if(file_exists($inputFileName))
                                    {
                                        $inputFileType = PHPExcel_IOFactory::identify($inputFileName);
                                        $objReader = PHPExcel_IOFactory::createReader($inputFileType);
                                        $objReader->setReadDataOnly(true);
                                        $objPHPExcel = $objReader->load($inputFileName);

                                        //to obtain date from FILE and store in DB for future comparison
                                        $validating_date_reporting = $objPHPExcel->getSheet(0)->getCell('C10')->getValue();
                                        $validating_date_reporting = PHPExcel_Style_NumberFormat::toFormattedString($validating_date_reporting,"YYYY-MMM-DD");
                                        $validating_date_reporting = date('Y-m-d',strtotime($validating_date_reporting));

                                        //first entry
                                        $entry = mysql_query('INSERT INTO `'.$table.'`(`broker_code`, `date`, `date_from_submission`) VALUES("'.$broker_code.'","'.$reporting_date.'","'.$reporting_date.'")') or die(mysql_error());

                                        foreach($cells_array as $caRef=>$sName)
                                        {
                                            foreach($sName as $sNameRef=>$cells)
                                                {

                                                    $wksht_page = array_search($caRef, $sheetNameArray);
                                                    $cell_column = $wksht_page.'_'.$cells;
                                                    echo $inputFileName.' '.$caRef.' '.$cell_column.'<br>';
                                                    $value = $objPHPExcel->setActiveSheetIndexByName($caRef)->getCell($cells)->getCalculatedValue();

                                                    echo $value.'<br>';

                                                        if($value)
                                                        {
                                                            $isdPortal->LoginDB($db_periodic_submission);
                                                            $record = mysql_query('UPDATE `'.$table.'` SET `'.$cell_column.'` = "'.$value.'" WHERE broker_code = "'.$broker_code.'" AND date_from_submission = "'.$validating_date_reporting.'"') or die(mysql_error());

                                                        }

                                                }

                                        }


                                    }

I really hope that you can help me out here..

thank you in advance.

Answer 1

PHPExcel holds a calculation cache as well, and this is not cleared when you unset a workbook: it has to be cleared manually using:

PHPExcel_Calculation::flushInstance();

or

PHPExcel_Calculation::getInstance()->clearCalculationCache();

You can also disable calculation caching completely (although this may slow things down if you have a lot of formulae that reference cells containing other formulae) using:

PHPExcel_Calculation::getInstance()->setCalculationCacheEnabled(FALSE);

before you start processing your files

This is because currently PHPExcel uses a singleton for the calculation engine. It is in the roadmap to switch to using a multiton pattern later this year, which will effectively maintain a separate cache for each workbook, alleviating this problem.

EDIT

Note that simply unsetting $objPHPExcel does not work. You need to detach the worksheets before unsetting $objPHPExcel.

$objPHPExcel->disconnectWorksheets();
unset($objPHPExcel);

as described in section 4.3 of the Developer Documentation. And this is the point where you should also add the PHPExcel_Calculation::flushInstance();