Characteristics of Oracle

Quoted identifier is case-sensitive in Oracle

For oracle, identifier such as table name or column name can be quoted with double quotation mark (").
Quoted identifier can be oracle reserved word such as comment, check, add, group, lock or set. But unlike non-quoted identifier, quoted identifier is case sensitive.

Empty string is treated as a null

Oracle treats a character value with a length of zero(empty string) as null.
So, the following statement would set null to descn column of produt of which id is 'PD100'.

insert into products (id, name, descn) values ('PD100', 'Vega', '');

Oracle says that this may not continue to be true in future releases, but it seems very difficult to change this feature.


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