Description:
------------
The error message reported if an executed statement fails allways suggests that the failure may have occured due to 
concurrent updates. This is missleading as many errors can
cause the return count/return status to be zero

Reproduce code:
---------------
The code can be found in SDO/DAS/Relational/DatabaseHelper.php

$pdo_stmt->execute($value_list);
$rows_affected = $pdo_stmt->rowCount();
if ($rows_affected != 1) {
  $pdo_error_info = $pdo_stmt->errorInfo();
  $msg = "\nSDO/DAS/Relational.php::applyChanges encountered an error when attempting to execute $stmt";
  if ($rows_affected == 0) {
 $msg .= "\nPDO reported no rows affected by the SQL statement.";
 $msg .= "\nThis may happen if the data that was retrieved and updated has been changed by another processs in the database in the meantime.";
			}

Expected result:
----------------
If the rows affected == 0 this may just be because some other  SQL error has occured. This message leads you off looking for concurrency problems. The issue here is that the collision detection algorithm uses a "where" clause that returns $rows_affected == 0 if data on the database doesn't match data in an update. We should check that there are no SQLSTATE error s before writing this string


Actual result:
--------------
The error message as described