Hr and scott in oracl 12 c

Question

hi all ,
i know oracle 10 g excelent  ,
but iam new  to oracle 12 c
after installtion i tried to connect  to sql developer
i tried to make connection finally i do the connection with auto generated  local connections
connect as  SYSTEM ,system-orcl
have alook around user in all these connections , seems that the db is CDB
iam trying to connect to scott and hr  iknow that they are Pdb
after search if ound this way
CREATE TRIGGER open_all_pdbs
AFTER STARTUP
ON DATABASE
BEGIN
EXECUTE IMMEDIATE 'alter pluggable database all open';
END open_all_pdbs;
it's created  iam trying to connect like this 
CONN SYS/orcl @pdborcl as sysdba
prombet appear asking about name (sys)-another prombet asking about  password(orcl)-another one appear  asking  enter tns_admin (do n't know what 's this ) i leav it blank  then
error appear as error at line 1  connection faild
i tried  another way connectiong  from plsql
by writing  connect sys@pdborcl as sysdba
asking about password and then ora 12154 apperas said tns could not resolve  the connect identifier specified
any one have any idea about connectiong to hr or scott through sql dev or through plsql ?
plz  do not mention for this link https://forums.oracle.com/message/11199727#11199727  as it 's helpfull for me
hope that any one answer me
thanks and regards

Answer 1

any one have any idea about connectiong to hr or scott through sql dev or through plsql ?
plz  do not mention for this link https://forums.oracle.com/message/11199727#11199727  as it 's helpfull for me
hope that any one answer me
Why not mention that link? You said you wanted help with your problem and my reply at that link fully explains your problem and what you have to do to solve it. There are also links to two more threads that have more info about your issue.
This is a sql developer issue, so you should repost it in the sql developer forum.
https://forums.oracle.com/community/developer/english/development_tools/application_development_in_pl_sql/sql_developer_(not_for_general_sql_plsql_questions)
You can use a BASIC connnection in sql developer instead of the TNS connection you are trying to use. Those links explain how to do that.