Question

Been very frustrating but mysql is returning an empty set for this code (not echoing exists) :

if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
  mysql_select_db("repository", $con);

$url = stripslashes($url);
$url = mysql_real_escape_string($url, $con); 
$exists = mysql_query("SELECT url FROM sites WHERE url = '$url' LIMIT 1");
 if (mysql_num_rows($exists) == 1) {
    echo "exists";
 } 

it should not be doing this because I’ve tested a good amount.

The table consists of one column “url”, it is datatype varchar(1000) (the maximum). the url stored for test purposes is http://en.wikipedia.org/wiki/Thailand

Answer 1

Here’s what you do as a first step. Remove the WHERE url = '$url' from your query altogether and print out mysql_num_rows($exists) before using it.

That should be enough to tell if it’s one of the two likeliest problems:

• bad URL resulting in no rows being returned; or
• bad row caused by database containing other than you expect.

Based on your comments to date, the former is the most likely. If it turns out you get a row back without the where clause, you’ll have to figure out why your URL is incorrect. This may be a case-sensitivity issue or a padding (size) issue, among other things.

---

If, as you mention in a comment, like works where = doesn’t, then we need to see your data.

Execute (at the DB level):

select concat('[',url,']') from sites

and show us exactly what the output is. Similarly, output the URL being used by the code with something like:

print_r($url)

immediately before executing the mysql_query.

Please append the output from both those commands to your question.