How about simple aggregation? Sample data in lines #1 - 5; query that does the job begins at line #6.
SQL> with test (rec_dt, a, b, c) as
2 (select date '2021-01-01', 1, 0, 0 from dual union all
3 select date '2021-01-01', 0, 2, 0 from dual union all
4 select date '2021-01-01', 0, 0, 5 from dual
5 )
6 select rec_dt,
7 sum(a) as a,
8 sum(b) as b,
9 sum(c) as c
10 from test
11 group by rec_dt;
REC_DT A B C
---------- ---------- ---------- ----------
2021-01-01 1 2 5
SQL>
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