delete $dbh->{RaiseError};

##</code><code>##


# at this point RaiseError is off as per default connection
{
local $dbh->{RaiseError} = 1;
LABEL_START_TRANSACTION1:    
    eval {        
        # prepare the sql statement
        $sth = $dbh->prepare($sql);
        
        # execute the sql statement
        $sth->execute();
    };
}

if ($@)
{
   .. handle the error
}