Insert into database -only- if not already in database?

[listenmirndt]

Hi, Im trying to create a database which mirrors folders & files in those folders, the below code works fine, -but- Id like it to be able to update the database as new files are uploaded,

Running the script twice creates duplicate entries, where I only want the new files to be insert, & I cant truncate the database prior, as it will contain other info - Thanks for any help!

<?php

$folderarray = array();
if ($dir = @opendir("gallery/")) {
while (($folder = readdir($dir)) !== false) {
if ($folder != "." && $folder != "..") {
$folderarray[] = $folder;

$filearray = array();
if ($fil = @opendir("gallery/$folder/")) {
while (($file = readdir($fil)) !== false) {
if ($file != "." && $file != "..") {
$filearray[] = $file;

$sql = "INSERT INTO GALLERY SET FOLDER='$folder', FILE='$file'";
$query = mysql_query($sql) or die("Cannot query the database.<br>" . mysql_error());

}
}
closedir($fil);
}
}
}
closedir($dir);
}

?>

[ZibingsCoder]

MIght want to consider running a SELECT query before running the INSERT query. Run the SELECT query, checking for an entry with the same values $folder and $file, then if it returned no results (mysql_num_results($query) == 0), you know there aren't any entries like it and you can proceed with the INSERT query. If mysql_num_results($query) returns 1 or more, then you know not to run the INSERT query.

Hope this helps!

[Erestar]

Might wanna use mySQL's REPLACE functionality.

Check it out here.