Query using TO_DATE TO_CHAR failing with ORA-01858 or ORA-01843
(Doc ID 790098.1)
Last updated on NOVEMBER 25, 2019
Applies to:
Oracle Database - Enterprise Edition - Version 9.2.0.1 and laterOracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.
***Checked for relevance on 02-Jul-2012***
Symptoms
NOTE: In the images and/or the document content below, the user information and environment data used represents fictitious data from the Oracle sample or bulit-in schema(s), Public Documentation delivered with an Oracle database product or other training material. Any similarity to actual environments, actual persons, living or dead, is purely coincidental and not intended in any manner.
An error is being generated on some clients when executing a query using TO_DATE(TO_CHAR .
The errors indicate the data is invalid for what is expected to be returned. If you add/change a query hint the error may change slightly.
You may see:
ORA-01858: a non-numeric character was found where a numeric was expected
ORA-01843: not a valid month
An example of the scenario:
The DATA in SCOTT.EMP is as follows:
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
------- ---------- --------- ---------- --------- ----- ------- ----------
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
8000 HAMBURGLAR THIEF 7698 03-MAR-09 100 30
------- ---------- --------- ---------- --------- ----- ------- ----------
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
8000 HAMBURGLAR THIEF 7698 03-MAR-09 100 30
SQL> alter session set NLS_DATE_FORMAT='MM/DD/YYYY';
Session altered.
SQL> alter session set NLS_TIMESTAMP_FORMAT='YYYY-MM-DD-hh24.mi.ss.ff';
Session altered.
SQL> select *
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
select * from scott.emp where job='THIEF' and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'))
*
ERROR at line 1:
ORA-01858: a non-numeric character was found where a numeric was expected
SQL> select /*+ rule*/*
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
select /*+ rule*/* from scott.emp where job='THIEF' and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'))
*
ERROR at line 1:
ORA-01843: not a valid month
Session altered.
SQL> alter session set NLS_TIMESTAMP_FORMAT='YYYY-MM-DD-hh24.mi.ss.ff';
Session altered.
SQL> select *
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
select * from scott.emp where job='THIEF' and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'))
*
ERROR at line 1:
ORA-01858: a non-numeric character was found where a numeric was expected
SQL> select /*+ rule*/*
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
select /*+ rule*/* from scott.emp where job='THIEF' and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'))
*
ERROR at line 1:
ORA-01843: not a valid month
Once the NLS Formats are changed back the query now executes without error:
SQL> alter session set NLS_DATE_FORMAT='DD-MON-RR';
Session altered.
SQL> alter session set NLS_TIMESTAMP_FORMAT='DD-MON-RR HH.MI.SSXFF AM';
Session altered.
SQL> select *
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
no rows selected
SQL> select /*+ rule*/*
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
no rows selected
Session altered.
SQL> alter session set NLS_TIMESTAMP_FORMAT='DD-MON-RR HH.MI.SSXFF AM';
Session altered.
SQL> select *
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
no rows selected
SQL> select /*+ rule*/*
from scott.emp
where job='THIEF'
and TO_DATE(TO_CHAR(HIREDATE, 'DD-MON-YY')) = TO_DATE(TO_CHAR(sysdate-1, 'DD-MON-YY'));
no rows selected
Changes
A session, instance, or database NLS parameter has changed or you may have upgraded clients.
Cause
To view full details, sign in with your My Oracle Support account. |
|
Don't have a My Oracle Support account? Click to get started! |