Oracle 18c

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CREATE TABLE TEMP_TEST (
    CODE NUMBER,
    DATE_COL NUMBER,
    VAL NUMBER
);
BEGIN
INSERT INTO TEMP_TEST (code, DATE_COL, val) values (1, 20210101, 1);
INSERT INTO TEMP_TEST (code, DATE_COL, val) values (1, 20210102, 2);
INSERT INTO TEMP_TEST (code, DATE_COL, val) values (1, 20210103, 3);
INSERT INTO TEMP_TEST (code, DATE_COL, val) values (2, 20210101, 4);
END;
/
1 rows affected

SELECT t.code,
       d.date_col,
       COALESCE(t.val, 1) AS val
FROM   (
         SELECT DISTINCT date_col FROM temp_test
       ) d
       LEFT OUTER JOIN temp_test t
       PARTITION BY (t.code)
       ON (t.date_col = d.date_col);


CODE
DATE_COL
VAL


1
20210101
1

1
20210102
2

1
20210103
3

2
20210101
4

2
20210102
1

2
20210103
1


SELECT DISTINCT
       t.code,
       d.date_col,
       t.val
FROM   (SELECT DISTINCT date_col FROM temp_test) d
       CROSS JOIN temp_test t
ORDER BY code, date_col


CODE
DATE_COL
VAL


1
20210101
1

1
20210101
2

1
20210101
3

1
20210102
1

1
20210102
2

1
20210102
3

1
20210103
1

1
20210103
2

1
20210103
3

2
20210101
4

2
20210102
4

2
20210103
4


select distinct a.code, b.date_col, c.val
from temp_test a cross join temp_test b cross join temp_test c
order by 1, 2, 3;


CODE
DATE_COL
VAL


1
20210101
1

1
20210101
2

1
20210101
3

1
20210101
4

1
20210102
1

1
20210102
2

1
20210102
3

1
20210102
4

1
20210103
1

1
20210103
2

1
20210103
3

1
20210103
4

2
20210101
1

2
20210101
2

2
20210101
3

2
20210101
4

2
20210102
1

2
20210102
2

2
20210102
3

2
20210102
4

2
20210103
1

2
20210103
2

2
20210103
3

2
20210103
4
CODE	DATE_COL	VAL
1	20210101	1
1	20210102	2
1	20210103	3
2	20210101	4
2	20210102	1
2	20210103	1