Encrypting Database Entries

<?php

$success = true;
//start transaction
$command = “SET AUTOCOMMIT=0”;
$result = mysqli_query($db, $command);
$command = “BEGIN”;
$result = mysqli_query($db, $command);

$command = “SELECT tablename.id, tablename.username from tablename “;
$result = mysqli_query($db, $command);
if ($result && mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_assoc($result)) {
echo “<br/><br/>Result 1 is:”.$result.”<br/><br/>”;
$myids = $row[‘id’];
$user_name = $row[‘username’];
$user_name= md5($user_name);
echo “hello”.$user_name;
$command2 = “UPDATE tablename SET username=’$user_name’ WHERE id=’$myids’ ORDER BY id DESC”;
$result2 = mysqli_query($db, $command2);
echo “<br/><br/>Result 2 is”.$result2.” and id is “.$myids.” and encrypted username is “.$user_name.””;
if (($result == false) ||
(mysqli_affected_rows() == 0)) {
$success = false;
}
}
}

$command = “COMMIT”;
$result = mysqli_query($db, $command);
#set session variable
$command = “SET AUTOCOMMIT=1”;  //return to autocommit
$result = mysqli_query($db, $command);
?>

$command = “SELECT tablename.id, tablename.username from tablename “;
$result = mysqli_query($db, $command);
if ($result && mysqli_num_rows($result) > 0){
while($row = mysqli_fetch_assoc($result)) {
echo “<br/><br/>Result 1 is:”.$result.”<br/><br/>”;
$myids = $row[‘id’];
$user_name = $row[‘username’];
$user_name= md5($user_name);
echo “hello”.$user_name;
$command2 = “UPDATE tablename SET username=’$user_name’ WHERE id=’$myids’ ORDER BY id DESC”;
$result2 = mysqli_query($db, $command2);
echo “<br/><br/>Result 2 is”.$result2.” and id is “.$myids.” and encrypted username is “.$user_name.””;

}
}