Hope all of you are fine and doing good.
Basically I have been working on sql-developer for like 3-4 months.(using database 11g). In it I simply used to make a sys connection, then by right clicking the "other Users" I used to make the new user with "DBA" and "CONNCET" Roles. Then by right-clicking the "NewConnections", I used to make a "new connection" for that particular user(which I created in SYS).
And it all used to work perfectly.
Now from since I am using oracle 12c, I am facing some issues.
Firstly I just wanted to know whether the things I did for creating a "new Connection" in 12c, are correct or not.
At first, I created a "pluggable database" by the name pdb0.
Secondly I altered the session using the SQL command:
SQLstatement---alter session set container=pdb0----SQLstatement
After that, I created a "new User" under SYS, by right clicking the "other Users" and assigned the "DBA" and "CONNCET" Roles to it.
Then by right-clicking the "NewConnections", I made a "new connection" for that particular user(which I created in SYS).
As I was unable to give SID: orcl (as in 11g).
Question#1) Is this the right way to make a user in 12c?
Question#2) When I used the expdp command to export my user I recently created it gave the error ORA-12537. (TNS: connection closed).
provides short assistance for data pump export, which is useful if you know what you want to do. On the other hand, Oracle 12c Data Pump Export documentation explains it in details. If you didn't read it yet, consider to do it now.
As dump files are created on a server, you have to have a directory object available to user which performs export. I don't see you using DIRECTORY in the command you posted, so - that might be one reason for EXPDP to fail.
As you said - various commands result in various errors. It is difficult to guess what you did as you didn't share that information with us. However, I believe that - after carefully reading documentation - you'll manage to do it.
As of the way you use to create users - sorry, I don't do that using SQL Developer so I don't know whether you missed something or not. I rely on good old SQL*Plus and manually typed CREATE USER ...