Monthly statistics. ORA-01722: Invalid number - sql

Question

I use two choices to make monthly statistics. The first select selects the appropriate data, and then carefully counts the monthly statistics.
First select：
SELECT
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD') AS DA,
ID,
MAX (DAYRF) AS DAYRF
FROM
JC_T_QXJYJCSJ
WHERE
ID = 'G2001'
GROUP BY
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD'),
ID
ORDER BY
ID,
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD')
the result:
result
the final code:
SELECT
TO_CHAR (DA, 'RRRR-MM') AS DA1,
SUM (DAYRF)FROM(
SELECT
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD') AS DA,
ID,
MAX (DAYRF) AS DAYRF
FROM
JC_T_QXJYJCSJ
WHERE
ID = 'G2001'
GROUP BY
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD'),
ID
ORDER BY
ID,
TO_CHAR (ZDZDATETIME, 'RRRR-MM-DD')
) GROUP BY
TO_CHAR (DA, 'RRRR-MM');
Always prompt me for invalid numbers
I think the ID=‘G2001’ sentence has a problem, so I tried to change it to other ID='XXX' and it will run successfully. I don’t know if an error other than code has occurred.

Answer 1

Your question did not reveal much information about your issue.
I tried to convert your question into one problem statement and resolved the same using following query.
WITH DATAA(ID, DAYRF, DATE1) AS
(
SELECT 1, 10, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 1, 9 , DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 1, 5, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 2, 20, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 2, 15, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 2, 12, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 3, 5, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 3, 30, DATE '2019-06-22' FROM DUAL UNION ALL
SELECT 1, 20, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 1, 29 , DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 1, 15, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 2, 40, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 2, 45, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 2, 32, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 3, 19, DATE '2019-06-23' FROM DUAL UNION ALL
SELECT 3, 1, DATE '2019-06-23' FROM DUAL
)
SELECT
DATE1,
SUM(MAX_DAYRF)
FROM
(
SELECT
DATE1,
ID,
MAX(DAYRF) AS MAX_DAYRF
FROM
DATAA
GROUP BY
DATE1,
ID
)
GROUP BY
DATE1;
Ouptut
Fiddle Demo
Cheers!!