How can PHP developers check if a file input is empty and prevent updating database records if no new file is uploaded?

To check if a file input is empty in PHP, developers can use the `$_FILES` superglobal to check if the 'tmp_name' key is empty. To prevent updating database records if no new file is uploaded, developers can first check if a new file is uploaded using the `$_FILES` superglobal. If a new file is uploaded, update the database records with the new file. If no new file is uploaded, do not update the database records. 

if(!empty($_FILES['file']['tmp_name'])) {
    // File is uploaded, update database records
    $file = $_FILES['file']['name'];
    // Update database records with the new file
} else {
    // No file uploaded, do not update database records
    echo "No file uploaded.";
}

Keywords

PHP file input empty database records uploading

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