Remove Line From CSV File

Question

I have .csv file with 4 columns. What's the easiest way to remove a line identical with the id of the first column? Here's where I got stuck:

if($_GET['id']) {
    $id = $_GET['id'];
    $file_handle = fopen("testimonials.csv", "rw");

    while (!feof($file_handle) ) {
        $line_of_text = fgetcsv($file_handle, 1024);    
        if ($id == $line_of_text[0]) {
            // remove row
        }
    }
    fclose($file_handle);
}

Unfortunately, databases were not a choice.

Solution 1

$id = $_GET['id'];
if($id) {
    $file_handle = fopen("testimonials.csv", "w+");
    $myCsv = array();
    while (!feof($file_handle) ) {
        $line_of_text = fgetcsv($file_handle, 1024);    
        if ($id != $line_of_text[0]) {
            fputcsv($file_handle, $line_of_text);
        }
    }
    fclose($file_handle);
}

Solution 2

$table = fopen('table.csv','r');
$temp_table = fopen('table_temp.csv','w');

$id = 'something' // the name of the column you're looking for

while (($data = fgetcsv($table, 1000)) !== FALSE){
    if(reset($data) == $id){ // this is if you need the first column in a row
        continue;
    }
    fputcsv($temp_table,$data);
}
fclose($table);
fclose($temp_table);
rename('table_temp.csv','table.csv');

Solution 3

I recently did a similar thing in for a newsletter unsubscription, heres my code:

$signupsFile = 'newsletters/signups.csv';
$signupsTempFile = 'newsletters/signups_temp.csv';
$GLOBALS["signupsFile"] = $signupsFile;
$GLOBALS["signupsTempFile"] = $signupsTempFile;


function removeEmail($email){
    $removed = false;
    $fptemp = fopen($GLOBALS["signupsTempFile"], "a+");
    if (($handle = fopen($GLOBALS["signupsFile"], "r")) !== FALSE) {
        while (($data = fgetcsv($handle)) !== FALSE) {
        if ($email != $data[0] ){
            $list = array($data);
            fputcsv($fptemp, $list);
            $removed = true;
        }
    }
    fclose($handle);
    fclose($fptemp);
    unlink($GLOBALS["signupsFile"]);
    rename($GLOBALS["signupsTempFile"], $GLOBALS["signupsFile"]);
    return $removed;
}

this uses the temp file method of writing out the csv line by line to avoid memory errors. Then once the new file has been created, it deletes the original and renames the temp file.

You can modify this code so that it looks for an ID instead of an email address eg:

$id = $_GET['id'];  
$fptemp = fopen('testimonials-temp.csv', "a+");
if (($handle = fopen('testimonials.csv', "r")) !== FALSE) {
    while (($id= fgetcsv($handle)) !== FALSE) {
    if ($id != $data[0] ){
        $list = array($data);
        fputcsv($fptemp, $list);
    }
}
fclose($handle);
fclose($fptemp);
unlink('testimonials.csv');
rename('testimonials-temp.csv','testimonials.csv');

Comments

[Byron Whitlock]

You are forgetting the part where you write out the csv array to another file. You also don't want to store the whole csv in an array becuause it could lead to out of memory errors. Better to write the csv out incrementally.