Question

I have an issue in a PHP script which checks if the tax number has right company name on input some other form fields and insert into MySQL. What I want is to put some control code – maybe “select distinct formCompany from company where formCompany = “.$formCompany.” ” or some code which checks if taxid is given correctly for the name of company from input form. Does someone have idea of how to do that? Any example is welcome.

I have script which simply input data from form fields into MySQL db:

$db=mysql_connect($hostname, $db_user, $db_password);
    mysql_select_db($database,$db);
$taxid=mysql_real_escape_string($_POST['taxid']);
$formCompany=mysql_real_escape_string($_POST['formCompany']);
$formOffice=mysql_real_escape_string($_POST['formOffice']);
$formBr=mysql_real_escape_string($_POST['formBr']);
$formContact=mysql_real_escape_string($_POST['formContact']);
//trim
$id=trim($id);
$taxid=trim($taxid);
$formCompany=trim($formCompany);
$formOffice=trim($formOffice);
$formBr=trim($formBr);
$formContact=trim($formContact);
if($_POST['taxid']==''||$_POST['formCompany']=='') {
       echo '<p style="color: red">Input relevant data!<p>';
   } else { 
      $sql = "INSERT INTO company (taxid, formCompany,formOffice,formBr,formContact) VALUES ('$taxid','$formCompany','$formOffice','$formBr', '$formContact')";
   if(!$result = mysql_query($sql, $db)) {
      echo "ERROR: ".mysql_error();
   } else {
      header("Refresh: 0; url=main.php");
   }
}

Answer 1

First, add this code before the if statement

$taxcheck = mysql_query("SELECT * FROM company WHERE taxid = '" . $taxid . "' ");
if (mysql_num_rows($taxcheck)) { $exists = true; }
else { $exists = false; }

Then change this line

if($_POST['taxid']==''||$_POST['formCompany']=='')

to

if($_POST['taxid'] == "" || $_POST['formCompany'] == "" || $exists == true)

This code will prevent you from ending up with more than one company using one tax ID number.