Why so many conflicting pieces of information I am getting on Oracle's default DATE format?

Question

First time using Oracle SQL (I'm used to MySQL). I'm finding conflicting info on what the default date format is. After several attempts having to use TO_DATE with my INSERT INTO my table statements, I finally found the database I'm using expects DD-MON-YY (i.e. 25-JAN-18). Yet on various pages here in stackoverflow and elsewhere, I see some that say default is YYYYMMDD or DD/MM/YYYY or YYYY-MM-DD. Why so many conflicting pieces of information?

Answer 1

Oracle  database allows you to set the default format. Out of the box, the format is (typically) DD-MON-RR, where "RR" refers to a two-digit year. This is a pretty lousy format, from the perspective of ambiguity (two digit year?) and internationalization (for what countries is that actually the default?). But Oracle has been around a long, long time.

 

In another format(Standard)  are also defined by ISO, the International Standards Organization. They settled on something more like YYYY-MM-DD. Actually, the hyphens are optional, but I think they make the date much more readable.

 

Oracle accepts constants in this format, if you use DATE:

 

select DATE '2021-02-11'