PHP - file not sending to database error - php

Question

I allow users to submit files into the database on my website. But every time a file is submitted, i get these error messages
( ! ) Warning: file_get_contents() expects parameter 1 to be a valid path, array given in C:\wamp64\www\MT\developerUpload.php on line 8
( ! ) Warning: trim() expects parameter 1 to be string, array given in C:\wamp64\www\MT\developerUpload.php on line 9
But I was told that "file_get_contents" is the way you send the file contents to the database. Without the "file_get_contents" it sends perfectly but with it, it gives me those error messages and I am not sure why. So what i want to do is, submit the file using the "file_get_contents" so later on i can display the content on the users page. Here is my code
PHP
$query = "INSERT INTO pack_screenshots(pack_id, file_name, file_tmp)VALUES(:packid, :file_name, :file_tmp)";
$stmtFileUpload = $handler->prepare($query);
$errors = array();
foreach($_FILES['file']['tmp_name'] as $key => $error){
if ($error != UPLOAD_ERR_OK) {
$errors[] = $_FILES['file']['name'][$key] . ' was not uploaded.';
continue;
}
$file_tmp = file_get_contents($_FILES['file']['tmp_name']);
$file_name = addslashes(trim($_FILES['file']['name']));
try{
$stmtFileUpload->bindParam(':packid', $packid, PDO::PARAM_STR);
$stmtFileUpload->bindParam(':file_name', $file_name, PDO::PARAM_STR);
$stmtFileUpload->bindParam(':file_tmp', $file_tmp, PDO::PARAM_STR);
$stmtFileUpload->execute();
$dir = "devFiles";
if(is_dir($dir)==false){
mkdir($dir, 0700);
}
if(is_file($dir.'/'.$file_name)==false){
move_uploaded_file($file_tmp,$dir.'/'.$file_name);
}else{
$_SESSION['invalid'] = true;
header("Location: developer_invalid.php");
exit;
}
$_SESSION['thankyou'] = true;
header("Location: developerUpload_thankyou.php");
exit;
}catch(PDOException $e){
$errors[] = $file_name . 'not saved in db.';
echo $e->getMessage();
}
}

Answer 1

Your problem is you have no keys associated with the 2 lines giving you an error (and probably elsewhere in your code), therefore they are arrays (as you are not selecting a specific key).
You need to associate the keys to the $_FILES array.
$file_tmp = file_get_contents($_FILES['file']['tmp_name'][$key]);
$file_name = addslashes(trim($_FILES['file']['name'][$key]));

Answer 2

Since you are using multiple uploads so you have to assign keys to them before proceed.
file_get_contents() and trim() accepts string here you pass array in it without assigning key.
Try this:
$file_tmp = file_get_contents($_FILES['file']['tmp_name'][$key]);
$file_name = addslashes(trim($_FILES['file']['name'][$key]));