my $returnValue;
$sth = $self->GetDatabase()->prepare( "CALL mySchema.myStoredProcedure(?,?,?)" );
$sth->bind_param(1,$p1);
$sth->bind_param(2,$p2);
$sth->bind_param(3,0);
$sth->bind_param_inout(4,\$returnValue,20);
$sth->execute();
$sth->finish();