ORA-01843: Invalid month

By default, Oracle databases display dates in DD-MON-YY, where DD is the day, MON is the first three letters of the month (uppercase), and YY is the last two digits of the year. The database actually stores four digits for the year, but only the last two digits are displayed by default.

A simple statement:

SELECT TO_DATE ('21-MAY-2014 ') FROM dual;

Triggering ORA-01843: Invalid month!

PL/SQL Developer error:

Command line:

Vc/users + s6Osy/users + M7Sw8dTUUzT777ky/nV67bUtcS7t76zysfTos7Eu7e + authorization + cve-vcd4kpha + authorization = "-2014 ') FROM dual;

Unified English:

1. Modify the language of the Client SESSION Date: alter session set nls_date_language = 'American ';

2. Successful execution: SELECT TO_DATE ('21-MAY-2014 ') FROM dual;