File uploading, transfer and storage - php

Question

I'm creating a simple mail system in PHP. And I'm stuck in this situation. I want to add a feature where my system can also do a file uploading and transferring. But I don't know how to add the file into mysql database. Any tips would be appreciated
compose.php
<form class="form-horizontal" method="post" action="" id="someForm" enctype="multipart/form-data">
<fieldset>
<!-- Form Name -->
<legend>Compose Mail</legend>
<!-- Text input-->
<!-- Text input-->
<div class="control-group">
<label class="control-label" for="sendto">Send To: </label>
<div class="controls">
<input id="sendto" name="sendto" placeholder="Send To" class="input-xlarge cmps" type="text">
</div>
</div>
<!-- Text input-->
<div class="control-group">
<label class="control-label" for="title">Title: </label>
<div class="controls">
<input id="title" name="title" placeholder="Title/Subject" class="input-xlarge cmps" type="text">
</div>
</div>
<!-- Textarea -->
<div class="control-group">
<label class="control-label" for="body">Message: </label>
<div class="controls">
<textarea id="body" name="body" class="cmps"></textarea>
</div>
</div>
<div class="control-group">
<label class="control-label" for="file">File: </label>
<div class="controls">
<input id="file" name="file" type="file">
</div>
</div>
<button type="submit" id="button" class="btn btn-success" onclick="askForSubmit()">Send!</button>
<button type="submit" id="button" class="btn-danger btn" onclick="askForSave()">Save to drafts</button>
</fieldset>
</form>
<script>
form=document.getElementById("someForm");
function askForSave() {
form.action="http://rsantiago.mbchosting.ph/email/save.php";
form.submit();
}
function askForSubmit() {
form.action="http://rsantiago.mbchosting.ph/email/send.php";
form.submit();
}
</script>
the upload_file.php
<?php
$allowedExts = array("gif", "jpeg", "jpg", "png");
$temp = explode(".", $_FILES["file"]["name"]);
$extension = end($temp);
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/jpg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/x-png")
|| ($_FILES["file"]["type"] == "image/png"))
&& ($_FILES["file"]["size"] < 30000)
&& in_array($extension, $allowedExts))
{
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br>";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br>";
echo "Type: " . $_FILES["file"]["type"] . "<br>";
echo "Size: " . ($_FILES["file"]["size"] / 30000) . " kB<br>";
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br>";
if (file_exists("upload/" . $_FILES["file"]["name"]))
{
echo $_FILES["file"]["name"] . " already exists. ";
}
else
{
move_uploaded_file($_FILES["file"]["tmp_name"],
"upload/" . $_FILES["file"]["name"]);
echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "Invalid file";
}
?>
I just wanna know how to store the file into the database so when the user sends it to another user, it can be downloaded