What are common pitfalls when trying to save query results to a text file in PHP?

Common pitfalls when trying to save query results to a text file in PHP include not properly handling special characters, not checking if the file is writable, and not closing the file after writing to it. To solve these issues, make sure to properly escape special characters, check if the file is writable before writing to it, and close the file after writing to it to release system resources. 

<?php
// Connect to database and run query
$connection = mysqli_connect("localhost", "username", "password", "database");
$query = "SELECT * FROM table";
$result = mysqli_query($connection, $query);

// Check if file is writable
$filename = "results.txt";
if (is_writable($filename)) {
    // Open file and write query results
    $file = fopen($filename, "w");
    while ($row = mysqli_fetch_assoc($result)) {
        fwrite($file, implode(",", $row) . "\n");
    }
    fclose($file);
    echo "Query results saved to $filename";
} else {
    echo "Cannot write to $filename";
}

// Close database connection
mysqli_close($connection);
?>

Keywords

file_put_contents fopen fwrite file permissions error handling

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