What is the difference between varchar and varchar2 in Oracle?
Solution 1:
As for now, they are synonyms.
VARCHAR is reserved by Oracle to support distinction between NULL and empty string in future, as ANSI standard prescribes.
VARCHAR2 does not distinguish between a NULL and empty string, and never will.
If you rely on empty string and NULL being the same thing, you should use VARCHAR2.
Solution 2:
Currently VARCHAR behaves exactly the same as VARCHAR2. However, the type VARCHAR should not be used as it is reserved for future usage.
Taken from: Difference Between CHAR, VARCHAR, VARCHAR2