User error messages

[Arc]

I have a form where the user enters an Invoice Number. I check the Database to see if this Invoice Number is already in the DB. If it is then i display an error message.. if not then it's supposed to add it to the DB.

$Sql = "SELECT InvoiceNum FROM tblBuildingInvoices WHERE InvoiceNum = '$InvoiceNum'";
  $Result = mysql_query($Sql, $Connect);
  If ($Result > 0) $Error .= "There has already been an invoice with that number added<br>";

My problem is this returns the error message even if there is no Invoice by that number....any idea why?

Thanks!😃

[mjlively]

mysql_query returns a result resource not the number of rows. Use [man]mysql_num_rows[/man] to get the number of rows returned by a query.

$Sql = "SELECT InvoiceNum FROM tblBuildingInvoices WHERE InvoiceNum = '$InvoiceNum'";
  $Result = mysql_query($Sql, $Connect);
  If (mysql_num_rows($Result) > 0) $Error .= "There has already been an invoice with that number added<br>";

[Arc]

right..thanks alot 🙂