Help for date field value

Question

I want to manually modify something in our ERP system. But I find some fields in table which is in date type have the value '0000-00-00'. How can I insert the same value to the database?
Our DBMS is oracle 816.
SQL> select to_char(t$curd,'yyyy-mm-dd hh:mi:ss') from triton.ttdsls051702
2 where
3 t$orno = 104497;
TO_CHAR(T$CURD,'YYY
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
SQL> select to_date('0000-00-00' , 'yyyy-mm-dd') from dual;
select to_date('0000-00-00' , 'yyyy-mm-dd') from dual
ERROR at line 1:
ORA-01843: not a valid month
Please offer me some help. Thank you!

Answer 1

Oracle has some funny ideas about dates. I tried this on 8.0.6, 8.1.7 and 9.0.1.
SQL> SELECT TO_CHAR(TO_DATE('01-01-0001','dd-mm-yyyy'),'j') FROM dual;
TO_CHAR
1721424
SQL> SELECT TO_CHAR(TO_DATE('1721423','j'),'dd-mm-yyyy') FROM dual;
SELECT TO_CHAR(TO_DATE('1721423','j'),'dd-mm-yyyy') FROM dual
ERROR at line 1:
ORA-01841: (full) year must be between -4713 and +9999, and not be 0
but ...
SQL> SELECT TO_CHAR(TO_DATE('1721424','j')-1,'dd-mm-yyyy') FROM dual;
TO_CHAR(TO
00-00-0000
again but...
SQL> CREATE TABLE t (dt DATE);
Table created.
SQL> INSERT INTO t SELECT TO_DATE('1721424','j')-1 from dual;
1 row created.
SQL> ALTER SESSION SET nls_date_format = 'dd-mm-yyyy';
Session altered.
SQL> select * from t;
DT
31-12-0000
yet again but ...
SQL> SELECT TO_CHAR(dt,'dd-mm-yyyy') FROM t;
TO_CHAR(DT
00-00-0000I think it is probably safe to set those dates to null, or some other acceptable default value depending on what t$curd means in your application.
TTFN
John