Best way to account for incorrect entries

[dasmon777]

I am trying to come up with a better way to account for bad entries on a postcode form.

The form checks the postcode against a database and sends them to the right store. But it only works on the first 3 or 4 characters of the UK postcode.

I have looked through the forum, but can't find an exact equivalent of what I am doing.

This is the code I am up to - but clearly the structure is wrong, somewhow.

<?php

if(isset($_POST['Submit1'])){


  if (strlen($pcodesrch) >4) {  


 $pcodesrch = strtoupper(trim($postcode));


$pcodesrch = trim($_POST['pcodesrch']);


$pcodesrch = str_replace(" ","",$pcodesrch);

$postcode = substr($pcodesrch,0,strlen($pcodesrch)-3); 

// Conditional statement




if(!empty($pcodesrch)){
    // Connect to database
    $eg_objConn1 = mysql_connect("localhost", "xxxxx", "xxxx");
	mysql_select_db("xxxxxx", $eg_objConn1);        


    $pcode = mysql_real_escape_string($postcode);
    // Get Record Set
    $eg_recResult1 = mysql_query("SELECT pcode, urlref FROM destinate
                                WHERE pcode='".$pcode."'", $eg_objConn1);

    $num_rows = mysql_num_rows($eg_recResult1);
    if($num_rows){
        $eg_Result1 = mysql_fetch_array($eg_recResult1, MYSQL_ASSOC);
        // Go to page
        header("Location: ".$eg_Result1['urlref']."");
        exit();
    }
	}
	echo "We did not recognise your postcode, did you enter the postcode correctly?";
exit();


} elseif (strlen($pcodesrch) <4) { 

	if(!empty($pcodesrch)){
    // Connect to database
    $eg_objConn1 = mysql_connect("localhost", "xxxxxx", "xxxxx");
	mysql_select_db("xxxxxxx", $eg_objConn1);        


    $pcode = mysql_real_escape_string($pcodesrch);
    // Get Record Set
    $eg_recResult1 = mysql_query("SELECT pcode, urlref FROM destinate
                                WHERE pcode='".$pcode."'", $eg_objConn1);

    $num_rows = mysql_num_rows($eg_recResult1);
    if($num_rows){
        $eg_Result1 = mysql_fetch_array($eg_recResult1, MYSQL_ASSOC);
        // Go to page
        header("Location: ".$eg_Result1['urlref']."");
        exit();
    	}
			}
		 echo "We did not recognise your postcode, did you enter the postcode correctly?";
		exit();
		}




?> 

What am I doing wrong?

[dasmon777]

Sorry should have also explained I am trying to account for all variations of entry: i.e. for postcode CT19 6NP. I need the code to interpret:

CT19 6NP, ct19 6np, Ct19 6NP, ct196np, ct19, CT19 etc.

The important bit being CT19.
Also bearing in mind that there is also a different area coded CT1 9GH so it could be entered ct1 9gh, ct19gh, ct1, CT19GH etc.

[halojoy]

Hi. Save your Queen!

It should be possible to make a good [man]preg_match[/man] regular expression
that would catch if the code is correct or has wrong format.

UK Royal Mail Postcodes uses two groups of letters.
The longest is 4+3 chars.

Wikipedia: Postcodes_in_the_United_Kingdom#Format
http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Format

Format Example
A9 9AA 	        M1 1AA 
A99 9AA 	M60 1NW
AA9 9AA 	CR2 6XH 
AA99 9AA 	DN55 1PT
A9A 9AA 	W1A 1HQ 
AA9A 9AA 	EC1A 1BB 	

[dasmon777]

Thanks Halojoy

I can see where regexp might be useful but I am not sure how it can seperate all the options.

I need to pull out the front 2 or 3 or 4 charatcters from the entry, but how can it differentiate

E1 from an entry of e11bb?

What I need it to do is read the length of the entry - if it is 5 characters, then the first two must be the code I need

If the entry is 6 characters then it will be the first 3 characters that are needed.

If the entry is 3 caharacters then just those 3 characters would be the ones that are needed

I am not sure how regexp could be used in that way?

[halojoy]

First,
I do not think you should accept such as 'ct19e1b' as input.
People would know how an uk mail code looks. If they are not stupid.
They have seen it 100-1000 times on an envelope they got.

We should either accept only one group of 2-4 chars
or the full 5-7 chars in 2 groups and 1 space in between.

Here I call the first group, 2-4 chars for $code1
First I do some cleaning and putting it all in UPPERCASE.
If we do this cleaning and get a good, proper $code1
then the rest with [man]preg_match[/man]
will be easy.

Sanitize and formatting the input.
You can try with different strings for $input you can come up with.
Such values that people maybe would try to enter.

<?php

$input = ' ct199aa';

$error = '';
//uppercase, remove leadning trailing spaces
$clean = strtoupper(trim($input));
echo $clean.' ('.strlen($clean).')<br />';

// get first part, before the space
$words = explode(" ", $clean);
$code1 = $words[0];
echo $code1.'<br />';

//if correct length we can continue
$len = strlen($code1);
if($len>=2 && $len<=4){
	echo 'correct! time for the preg_match here';

}else{//else we do not bother = bad input
	$error = 'not a valid input. please go back try again';
}

echo $error;

?>

[dasmon777]

Thanks Halojoy

I took part of your code concepts and applied it here.

<?php

if(isset($_POST['Submit1'])){




$pcodesrch = trim($_POST['pcodesrch']);


$pcodesrch = strtoupper(trim($pcodesrch));

$pcodesrch = str_replace(" ","",$pcodesrch);


$len = strlen($pcodesrch);
if ($len>=7 && $len<8){
	$pcodesrch = substr($pcodesrch,0, 4);

	} elseif ($len>=6 && $len<7){
		$pcodesrch = substr($pcodesrch,0, 3);

		} elseif ($len>=5 && $len<6){
		$pcodesrch = substr($pcodesrch,0, 2);

}

// Conditional statement
if(!empty($pcodesrch)){
    // Connect to database
    $eg_objConn1 = mysql_connect("localhost", "xxxxx", "xxxxx");
    mysql_select_db("xxxxxxx", $eg_objConn1);
    $pcode = mysql_real_escape_string($pcodesrch);
    // Get Record Set
    $eg_recResult1 = mysql_query("SELECT pcode, urlref FROM destinate
                                WHERE pcode='".$pcode."'", $eg_objConn1);

    $num_rows = mysql_num_rows($eg_recResult1);
    if($num_rows){
        $eg_Result1 = mysql_fetch_array($eg_recResult1, MYSQL_ASSOC);
        // Go to page
        header("Location: ".$eg_Result1['urlref']."");
        exit();
    }
}
echo "<p>We did not recognise your postcode, did you enter the postcode correctly? </p> ";

echo "<br />you typed in ".$pcodesrch;
echo "<p>Click here to return <a href='http://www.xxxxxxx.com'> www.xxxxxxx.com </a></p><br />" ;

}

exit();
?>

It could probably be cleaner, but it works.

I did spend some time on pregmatch expressions but I think I would need a bit more practice with what they do and how to make them work first.

Thanks for your help