"not a valid month" while inserting timestamp into table - sql

Question

Error while trying to insert a query which transforms multiple merged date(eg.20230208065521019355) into proper timestamp format to a new column.
INSERT INTO NEWTABLE2(RC_DATETIME)
SELECT TO_CHAR(TO_TIMESTAMP(RC_TIMESTAMP, 'YYYY-MM-DD HH:MI:SS:FF'), 'YYYY-MM-DD HH:MI:SS.FF')
FROM NEWTABLE;
Upon just executing the SELECT statement I get the query but while including the INSERT I get the error of 'not valid month'.
Data within the RC_TIMESTAMP(VARCHAR) are the merged data which are as follows:
20230208065521019355, 20230208065523019356, 20230208065532019357, etc.
RC_DATETIME has VARCHAR(35) datatype.
I have tried reordering the format of TO_CHAR, 'YYYY-MM-DD HH:MI:SS.FF' to 'Mon-DD-YYYY HH:MI:SS.FF' to name a few.

Answer 1

From what you posted:
Source table:
SQL> CREATE TABLE newtable (rc_timestamp)
2 AS (SELECT '20230208065521019355' FROM DUAL);
Table created.
Target table:
SQL> CREATE TABLE newtable2
2 (rc_datetime VARCHAR2 (35));
Table created.
Insert:
SQL> INSERT INTO newtable2 (rc_datetime)
2 SELECT TO_CHAR (TO_TIMESTAMP (rc_timestamp, 'yyyymmddhh24missff6'),
3 'yyyy-mm-dd hh24:mi:ss:ff')
4 FROM newtable;
1 row created.
However, you'd rather store timestamps into a timestamp column, not as a string. What benefit do you expect? It causes problems in later data processing.
SQL> DROP TABLE newtable2;
Table dropped.
SQL> CREATE TABLE newtable2
2 (rc_datetime TIMESTAMP);
Table created.
SQL> INSERT INTO newtable2
2 SELECT TO_TIMESTAMP (rc_timestamp, 'yyyymmddhh24missff6') FROM newtable;
1 row created.
SQL>
You commented that you still have the "not a valid month" error.
It means that data - at position where TO_TIMESTAMP expects a valid month value (01, 02, ..., 12) - contains something else. What? No idea, you have all the data. Try to find it by selecting a substring (month starts at position 5 and takes 2 places):
SQL> SELECT rc_timestamp, SUBSTR (rc_timestamp, 5, 2) month FROM newtable;
RC_TIMESTAMP MO
-------------------- --
20230208065521019355 02
SQL>
Invalid data is most probably here:
SELECT rc_timestamp
FROM newtable
WHERE SUBSTR (rc_timestamp, 5, 2) NOT BETWEEN '01' AND '12';
Once you find invalid values, you'll decide what to do with it. Maybe you'll ignore those values (so you'd include appropriate where clause into the insert statement), or fix it (somehow; can't tell how as it depends on what you'll find), or ...
If you want to identify invalid values during insert, a simple option is a loop with an inner begin-exception-end block which lets you capture those values and still proceed with other row(s). Something like this:
create table invalid_values as
select id, value from source_table where 1 = 2;
begin
for cur_r in (select * from source_table) loop
begin
insert into newtable2 ...
exception
when others then
insert into invalid_values (id, value) values (cur_r.id, cur_r.value);
end;
end loop;
end;
Once you're done, select * from invalid_value so that you could deal with what's left.
That should be OK as you have 10.000 rows so loop won't take infinite time to complete. True, it will be slower than set-oriented operation, but ... you have to fetch invalid rows, somehow.