> why does CLAUSE ORDER BY in POSTAGE SQL must have CASE SENSITIVE, what is
> the basic thought? isn't it ORDER BY function is only just a filter
> shorting?
If you were a bond broker, you would probably consider a bond
rated 'AAa' different from one rated 'AAA'.
Case sensitivity is significant for many types of data, that's why
databases should always treat data as case sensitive by default.
For those applications where it doesn't matter, there are case-insensitive
searching and ordering options in PostgreSQL, and if you really don't
need the data in upper/lower case you can always force it to one or the
other with a 'before insert or update' database trigger.
--
Mike Nolan