ORA-01017 Invalid Username/Password in SQL Developer

Question

I installed Oracle 18c XE and SQL Developer 18.4, both are the latest.

Logged in with SYSTEM and created a user vbk in SQL Developer.

I see the user running select * from dba_users, but when I try to connect in SQL Developer, it says

ORA-01017 Invalid Username/Password

I tried to reset the password with SYSTEM user:

ALTER USER vbk IDENTIFIED BY xxx;

and I get

ORA-01918: user 'VBK' does not exist 

I see that in the message the user name is upper case, even though the user was created with lower case.

How to connect with the user?

Answer 1

As explained in this answer on SO, if you create a user (or any other identifier) in lowercase, you will have to always quote it when referencing, because by default Oracle (and other SQL databases, except may be Postgres) will convert unquoted identifiers to uppercase.

connect "vbk"/password

or

ALTER USER "vbk" IDENTIFIED BY xxx;

• EdStevens: And if that worked, there should be an important lesson learned .. when dealing with Oracle, never ever create an object (user, table, index, procedure, etc etc) by enclosing the name in double-quotes. If you simply 'create user fred', with no double quotes, you will be, effectively, case-insensitive. But if you 'create user "fred" ', you have created a case-sensitive name and will always to refer to it enclosed in double-quotes and in the exact same "CaSeSenSiTiviTY" as it was created.
• Alfabravo: This is really important even when working from SQL Developer, because it will decide by itself that you NEED your username in lowercase, surrounded by quotes, with not a single warning about it. Check in the "Other users" list, the username must be in UPPERCASE or, otherwise, you'll get this very same problem