Updating a Row in a CSV File

[shaunie]

Hi,

 

I have a CSV file with the following columns; id, name, email

 

How can I loop through the file and just update the fields in the row that matches the particular id?

 

[Eddy_J1]

Sorry if the answer isn't brilliant, it's my first post

 

Try using fopen to get the file contents and then use fgetcsv to parse the fields into an array, you can then loop through the array and change the rows for your particular id.

http://php.net/manual/en/function.fopen.php

http://www.php.net/manual/en/function.fgetcsv.php

 

It may be really resource hungry but i'm an amateur myself so I'm not sure, this is just how I would go about it, the PHP manual is very handy.

[shaunie]

Thanks 

 

I've got this so far but for some reason I am unable to open the file for reading and writing at the same time?

 

if(isset($_POST)){
$row = 1;
if (($handle = fopen("customers.csv", "r+")) !== FALSE) {
   while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
       $num = count($data);
       $row++;
       for ($c=0; $c < $num; $c++) {
        echo '$data[0] = ' . $data[0];
           if($data[0] == $_POST['customerId']){
            echo 'true';
            $data[1] = $_POST['name'];
            $data[2] = $_POST['email'];
           }
       
       }
       fputcsv($handle, $data);
   }
   fclose($handle);
}
}

 

[mac_gyver]

because the length of the data is likely different, you would need to write the output to a different/temporary file so that you don't corrupt the input file.

[shaunie]

Thank you, I have updated it so the file is closed for reading and then opened for writing, but it's still not editing the file...

if(isset($_POST)){
	$row = 1;	
	if (($handle = fopen("customers.csv", "r")) !== FALSE) {
	    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
	        $num = count($data);
	        $row++;
	        for ($c=0; $c < $num; $c++) {
	            // Customer ID exists so edit the record
	        	if($data[0] == $_POST['customerId']){
	            	$data[1] = $_POST['name'];
	            	$data[2] = $_POST['email'];	            
	            }
	       		
	        }	        
	    }
	    fclose($handle);
	}
	if (($handle = fopen("customers.csv", "w")) !== FALSE) {
		fputcsv($handle, $data);
	}
}

[Eiseth]

Try fputscsv http://php.net/manual/en/function.fputcsv.php

[shaunie]

Thank you, I am using fputcsv() but am having problems writing to the file, I am able to read from it... Could it be a permissions problem?

[mac_gyver]

the problem is your LOGIC.

 

you must open the input file for reading, open a separate new output file for writing. then as you loop through the lines from the input file, you replace/update the data if it matches the submitted post data, and you write each line (both the unchanged and the updated ones) to the output file.

[DavidAM]

the problem is your LOGIC.

 

you must open the input file for reading, open a separate new output file for writing. then as you loop through the lines from the input file, you replace/update the data if it matches the submitted post data, and you write each line (both the unchanged and the updated ones) to the output file.

Then rename the two files, so the next time the process is run, you get the "new" file as input.

 

By the way: if there is any possibility that the page will be submitted from two different users, or even browser tabs, at the same time, you will experience data loss. This is one of the reasons that a database is recommended for data processing.

[mac_gyver]

starting with the logic in this thread - http://forums.phpfreaks.com/topic/278189-csv-class-need-help-updating-a-csv-file/?hl=%2Btempnam you would end up with something that looks like -

$csvfile = 'customers.csv';

$tempfile = tempnam(".", "tmp"); // produce a temporary file name, in the current directory

if(!$input = fopen($csvfile,'r')){
    die('could not open existing csv file');
}
if(!$output = fopen($tempfile,'w')){
    die('could not open temporary output file');
}

while(($data = fgetcsv($input)) !== FALSE){
    if($data[0] == $_POST['customerId']){
        $data[1] = $_POST['name'];
        $data[2] = $_POST['email'];
    }
    fputcsv($output,$data);
}

fclose($input);
fclose($output);

unlink($csvfile);
rename($tempfile,$csvfile);

echo 'done';

 

[shaunie]

Thanks guys, unfortunately the above code doesn't work, which leads me to believe there is a permissions issue. I have even commented out the lines:

 

//unlink($csvfile);

//rename($tempfile,$csvfile);

 

and the temp file is not present in that directory...

[mac_gyver]

do you have php's error_reporting set to E_ALL and display_errors set to ON so that you would see all the php errors? if there's a permission problem, there would be a php error about it.

[shaunie]

thanks! I have included error reporting and I am indeed having a permissions issue!

[phong_ux]

Other way,

You should try this: http://handsontable.com/

by copy and paste to table. i mean you open csv from excel and paste to handsontable form.

they use PDO to control Mysql but i don't know to convert to standard Php Mysql

Edited June 5, 2013 by phong_ux

[litebearer]

Perhaps...

if(isset($_POST)){
    $needle = $_POST['customerId'];
    $new_line = $needle . "," . $_POST['name'] . "," . $_POST['email'];
    $lines = file("customers.csv");
    $c = count($lines);
    $i = 0;
    while($i<$c) {
     $t_array = explode(",", $lines[$i]);
     if($t_array[0] == $needle) { $lines[$i] = $new_line; }
     $new_data = $new_data . $lines[$i] . "\n";
     $i ++;
    }

    $file_handle = fopen("customers.csv", 'w');
    fwrite($file_handle, $new_data);
    fclose($file_handle);
}