Suppress ORA-01403: no data found excpetion - oracle

Question

I have the following code
SELECT SUM(nvl(book_value,
0))
INTO v_balance
FROM account_details
WHERE currency = 'UGX';
--Write the balance away
SELECT SUM(nvl(book_value,
0))
INTO v_balance
FROM account_details
WHERE currency = 'USD';
--Write the balance away
Now the problem is, there might not be data in the table for that specific currency, but there might be data for the 'USD' currency. So basically I want to select the sum into my variable and if there is no data I want my stored proc to continue and not throw the 01403 exception.
I don't want to put every select into statement in a BEGIN EXCEPTION END block either, so is there some way I can suppress the exception and just leave the v_balance variable in an undefined (NULL) state without the need for exception blocks?

Answer 1

select nvl(balance,0)
into v_balance
from
(
select sum(nvl(book_value,0)) as balance
from account_details
where currency = 'UGX'
);

Answer 2

SELECT L1.PKCODE L1CD, L1.NAME L1N, L1.LVL L1LVL,
L2.PKCODE L2CD, L2.NAME L2N, L2.LVL L2LVL,
L5.PKCODE L5CD, L5.NAME L5N,
INFOTBLM.OPBAL ( L5.PKCODE, :PSTDT, :PSTUC, :PENUC, :PSTVT, :PENVT ) OPBAL,
INFOTBLM.DEBIT ( L5.PKCODE, :PSTDT,:PENDT, :PSTUC, :PENUC, :PSTVT, :PENVT ) AMNTDR,
INFOTBLM.CREDIT ( L5.PKCODE, :PSTDT,:PENDT, :PSTUC, :PENUC, :PSTVT, :PENVT ) AMNTCR
FROM FSLVL L1, FSLVL L2, FSMAST L5
WHERE L2.FKCODE = L1.PKCODE
AND L5.FKCODE = L2.PKCODE
AND L5.PKCODE Between :PSTCD AND NVL(:PENCD,:PSTCD)
GROUP BY L1.PKCODE , L1.NAME , L1.LVL ,
L2.PKCODE , L2.NAME , L2.LVL ,
L5.PKCODE , L5.NAME
ORDER BY L1.PKCODE, L2.PKCODE, L5.PKCODE