REGEXP '^$email$'

Does that really work? It's not unheard-of for the same symbol to have different meanings depending on where it's used (here non-RegEx $ for "string" and then RegEx $ for "end of expression"), but just looking at it gives me the willies ;)

The part for the main login part works perfect--its either go if the right info is provided or no-go if the not the right info. That was the part:

$query = "select username, password" . " from members where binary username = '$username' and binary password = '$password' limit 1";
($username, $userword) = $dbh->selectrow_array($query);

if((!defined($username)) || (!defined($password)))
{
$loginmsg="Invalid Login Information";
}
elsif((defined($username)) && (defined($password))){ 
print"You Have Provided Accurate Information";
}

That works great. I'm trying to follow the same basic pattern for creating new users (or users modifying details) and if an email address or username is listed in a row by another user...print out an error and if the email address or username is not already taken then (as in the case of email addresses) validate it before entereing it into the db. I can't understand why something will work one time and not the next. Shouldn't I just be able to modify the code given to do something like:

$query = "select email" . " from members where binary email_addresses = '$email'limit 1";
($email) = $dbh->selectrow_array($query);

if(!defined($email)
{
print"That email address is already listed";
}
elsif(defined($email)
{ 
#validate the email address
}

I can't understand why something works in one script and not another. That was when I started (2 days ago) searching information about exact (case, char for char, etc.) and that is where I came up with some of the "atrocities" in the original post. Really frustrating as this is the final hurtle in my project.

REGEXP '^$email$'

@lucy24: Yes, that does look confusing. However, I think the "$email" should be replaced by the value of the $email variable by Perl (variable interpolation in double quoted strings in Perl, variable parsing in PHP) - although this would perhaps be worth checking?

Just curious regarding the SQL... why would you use a regular expression rather than a straight forward comparison when checking for an exact match?

hmmm. I went back to a "barebones" type of select/results type of statement and it is doing what it is supposed to do(imagine that). I'm going to wait till morning to pick up on it again. Armed with the fact that it is doing what it is expected to do I think it will be a matter of a little bit of re-structuring my validation/error methods. I'll repost after further investigation on the matter and include the answer.

good to hear that you have a working solution typomaniac

why would you use a regular expression rather than a straight forward comparison when checking for an exact match

I would wonder the same, as it can introduce new problems such as $email being 'example@example.com', the dot is going to match any character and would mean example@example.com is the same as example@exampleZcom

When this "problem" first surfaced I wasn't using any regex or anything fancy--just a smiple

my $query = "SELECT pobox" . " FROM adminmembers WHERE binary pobox = '$address' limit 1";
$address = $dbh->selectrow_array($query);
if(defined($address))
{
#print error message---i.e., that email address is already registered to another user(or something similar)
}

Like I said, it worked before so why not now? Truth is it was working but the problem began when in the

if(!defined($address))
{ #problem begins here as I tried to validate user input email information
}

I eliminated the part "if(!defined) because I only needed to know if it WAS defined. I was putting the email validation codes inside the brackets of !undefined and that is where the problem began. I didn't need the !undefined part because if not defined---well, its either night or day. I learned a big lesson on this one.
As far as the regex? Well, instead of just going back to basics and using something like

if(defined($address))
{ 
print"That Address Is Taken";
}

And based on the fact that if it did not come true by not being defined just run the email validation instead of being concerned about it not being defined. Actually, I didn't know anything about using regex with mysql queries before I began searching for answers but I'm glad I did for future reference

Thanx for the replies. I learned as much from them as I did the searches.