SQL & PL/SQL

Hi all,

I am wondering if any one can tell me a better way to do what I am trying to do.
I am querying a table twice to get some values before I insert into the same table.
I am pretty sure there is a better way to do this.

select nvl(max(pd.line_no), 0) + 1
into p_new_line_no
from po_details pd
where pd.event_id = p_event_id;

select pd.cause, pd.cause_code
into l_cause, l_cause_code
from po_details pd
where pd.po_number = p_po_number
and pd.comp_code = p_comp_code
group by pd.comp_code;


insert into po_details
(qty, cost, cause, cause_code, line_no)
select p_qty, p_cost, l_cause, l_cause_code, p_new_line_no);

Thanks.