Making procedure to insert/update qty. What am I doing wrong? - sql

Question

I am trying to make procedure that count total slab # of from each pallet from prod_result table and insert or update that count to qty column in plt_result table that has same pallet #(plt_no)
I've tried insert, update both but doesn't work.
create or replace PROCEDURE update_qty
is
v_plt_no nvarchar2(20);
v_qty number;
cursor q1 is
select count(slab_no)
into v_qty
from prod_result
where plt_no = v_plt_no;
begin
if v_qty > 0 then
update plt_result
set qty = 'v_qty'
where plt_no = v_plt_no;
end if;
end;
What am I doing wrong here? Help please.

Answer 1

I'm not sure which version you're looking for - is it the one that loops through all PLT_NOs in a table, or the one that should accept PLT_NO as a parameter. Here are both options, see whether any of them helps.
The first one uses cursor FOR loop; it is easier to maintain as Oracle does most of the dirty job for you (opening the cursor, fetching, exiting the loop, closing the cursor).
create or replace procedure update_qty
is
begin
for cur_r in (select plt_no, count(slab_no) v_qty
from prod_result
group by plt_no
)
loop
if cur_r.v_qty > 0 then
update plt_result r set
r.qty = cur_r.v_qty
where r.plt_no = cur_r.plt_no;
end if;
end loop;
end;
The second one accepts PLT_NO as a parameter:
create or replace procedure update_qty
(par_plt_no in prod_result.plt_no%type)
is
v_qty number;
begin
select count(p.slab_no)
into v_qty
from prod_result p
where p.plt_no = par_plt_no;
if v_qty > 0 then
update plt_result r set
r.qty = v_qty
where r.plt_no = par_plt_no;
end if;
end;

Answer 2

Something like the following, where you actually open and fetch from the cursor. You'll have to assign a value to v_plt_no for the cursor to fetch anything.
create or replace PROCEDURE update_qty
is
v_plt_no nvarchar2(20);
v_qty number;
cursor q1 is
select count(slab_no)
into v_qty
from prod_result
where plt_no = v_plt_no;
begin
OPEN q1;
FETCH q1 INTO v_qty;
CLOSE q1;
if v_qty > 0 then
update plt_result
set qty = 'v_qty'
where plt_no = v_plt_no;
end if;
end;