Comparing 2 exact same strings returns false - php

Question

I have a variable that is posted through a html form:
$_POST['ref']
And a variable that is pulled from a table in a database:
$row['ref']
i have a basic comparison script to check if they are both the same:
$ref = $_POST['ref'];
$result = mysql_query("SELECT * FROM logbook.job");
if (!$result) {
die("Query to show fields from table failed");
}
$row = mysql_fetch_array($result);
$refdb = $row['ref'];
$refform = $_POST['ref'];
echo $_POST['ref'] ."<br>". $row['ref'] . "<br><br>";
if ($refdb == $refform) {
echo "Yes they are<br><br>";
}
else {
echo "No they are not<br><br>";
}
if (is_string($_POST['ref']))
{
echo "Yes";
} else {
echo "No";
}
echo "<br>";
if (is_string($row['ref']))
{
echo "Yes";
} else {
echo "No";
}
Which outputs:
G2mtxW
G2mtxW
No they are not
Yes
Yes
I echo them both out. Than i ask if they are the same. Then i check whether each is a string.
How come they are not the same? How can i get them to match
Any help would be appreciated

Answer 1

Try using the binary-safe comparison for String:
result = strcmp($str1, $str2);
If the result is 0, then both are the same. Otherwise, they aren't.

Answer 2

One of your strings (probably the one from the DB) might be null-terminated. I've tested the following
$foo = "abc\0";
$bar = "abc";
echo "$foo\n$bar\n";
if($foo == $bar)
echo "Equal.";
else
echo "Not equal."
Output is
abc
abc
Not equal.

Answer 3

Try var_dump-ing both values, check their lengths and inspect them using view-source. They are different in someway.

Answer 4

echo $status_message;
echo "Accepted";
if(strcmp($status_message,"Accepted")==0)
{
echo "equal";
}
else
{
echo "not equal";
}
?>
$row['status'] is a field from table