mysql value not found

I have a mysql table and am using php. I have:

mysql_query("SELECT id FROM table WHERE email='$email' LIMIT 1");

Now this开发者_开发百科 returns an ID if email was found. However, I want to do something if it does not find $email in the email table column. How can I recognise when $email was not found and tell php?

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mysql_query returns a result. You can call mysql_num_rows on that result to see the number of rows selected:

$result = mysql_query("SELECT id FROM table WHERE email='$email' LIMIT 1");
if (mysql_num_rows($result) > 0) {
    // found a result
} else {
    // no result found
}

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I think that mysql_num_rows check should help.

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If mysql_num_rows() returns 0, no row was selected because no email matched. http://docs.php.net/mysql_num_rows

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All that is required to check if a result was not found is an if statement used with the mysql_num_rows function:

$check = mysql_query("SELECT id FROM table WHERE email='$email' LIMIT 1");

$check2 = mysql_num_rows($check);

if ($check2 == 0) {
    // No email found, so show an error to the user
    echo "No email found!";
}
else
{
   // An email address was found, so do something with it here
}