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 IN

Answer 1

Oracle, as well as other databases, 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.

Standard formats 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 '2018-01-25'

This is very handy. First, it is nice to support reasonable standards. Second, the code is safe, regardless of internationalization settings. Oracle documentation of course covers this in detail; here is one place to start.