Modifying Insert data into table so that it is now Update Table - php

Question

Right now I am inserting blob files into a database. I have read up on the update syntax for mysql I can not figure out how to modify my code to update a row with the BLOB instead of inserting a new row with the BLOB. Could someone help me with this?
Here is my code:
<?php
// Create MySQL login values and
// set them to your login information.
$username = "root";
$password = "";
$host = "localhost";
$database = "test";
$tbl_name="members";
// Make the connect to MySQL or die
// and display an error.
$link = mysql_connect($host, $username, $password);
if (!$link) {
die('Could not connect: ' . mysql_error());
}
// Select your database
mysql_select_db ($database);
// Make sure the user actually
// selected and uploaded a file
if (isset($_FILES['image']) && $_FILES['image']['size'] > 0) {
// Temporary file name stored on the server
$tmpName = $_FILES['image']['tmp_name'];
// Read the file
$fp = fopen($tmpName, 'r');
$data = fread($fp, filesize($tmpName));
$data = addslashes($data);
fclose($fp);
// Create the query and insert
// into our database.
$query = "INSERT INTO members ";
$query .= "(image) VALUES ('$data')";
$results = mysql_query($query, $link);
// Print results
print "Thank you, your file has been uploaded.";
}
else {
print "No image selected/uploaded";
}
// Close our MySQL Link
mysql_close($link);
?>

Answer 1

1° You need to pass a referecence for what Data you are trying to update, like the Primary Key Id From Table.
2° Update SQL should be like it
$image = mysql_real_escape_string($unsafe_image);
$id = mysql_real_escape_string($unsafe_id);
$query = "UPDATE members SET image = '$data' WHERE id_image = $id";
$results = mysql_query($query, $link);