Oracle/ SQL Developer connection problem.

Question

I have installed Oracle 11 g and SQL Developer, When I open SQL Developer and try to make a new connection ( I name the connection, put a user name in, put my password in), I click on "Test" and I get this error:
Status: Failure - Test failed: Listener refused the connection with the followong error:ORA-12505, TNS: listener does not currently know of SID given in connect descriptor The connection descroptor used by the client was:localhost:1521:ex
Can anyone explain this to me and help me resolve this issue I am having?
Thank you in advance for your help
-steve
p.s. I have also tried the user name: Scott and Password: Tiger

Answer 1

Windows 7 Home ... will have challenges at some point, as Oracle may not be completely compatible with Windows 7.
Aside from that, you may find firewall issues even if you are on the same machine, since the default connection from SQLDeveloper is to use the network (even loopback).
First step is to verify that the database and listener are running and that the database is registered to the listener. TO do that, drop into command line and issue:
1) Listener
lsnrctl statuswhich will give one of two results, if properly installed. First - listener is down
C:\temp>lsnrctl status
LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 07-FEB-2010 20:48
:13
Copyright (c) 1991, 2005, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
  TNS-00511: No listener
   32-bit Windows Error: 2: No such file or directory
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=FCC003L)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
  TNS-00511: No listener
   32-bit Windows Error: 61: Unknown errorIf the above is displayed, check the Service applet (Control Panel -> Admin Tools > Service) to ensure serivce is up, or enter "lsnrctl start", in which case the status shoud show
C:\temp>lsnrctl status
LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 07-FEB-2010 20:46
:40
Copyright (c) 1991, 2005, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
Alias                     LISTENER
Version                   TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - Produ
ction
Start Date                05-FEB-2010 14:42:10
Uptime                    2 days 6 hr. 4 min. 30 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Default Service           XE
Listener Parameter File   C:\oracle\app\oracle\product\10.2.0\server\network\adm
in\listener.ora
Listener Log File         C:\oracle\app\oracle\product\10.2.0\server\network\log
\listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC_FOR_XEipc)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=FCC003L)(PORT=1521)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
  Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
C:\temp>2) After the service is verified up, make sure the database is up
sqlplus / as sysdbawhich should respond with something like
C:\temp>sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Feb 7 20:43:12 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
SQL>if it gives something like
C:\temp>sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Feb 7 20:44:49 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
ERROR:
ORA-12560: TNS:protocol adapter errorthe pull up the Control Panel, Admnistration Tools, Services and start the database. Then recheck the listener and it shoudl show some additional services such as
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "TEST" has 1 instance(s).
  Instance "xe", status READY, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
  Instance "xe", status READY, has 1 handler(s) for this service...
Service "XE_XPT" has 1 instance(s).
  Instance "xe", status READY, has 1 handler(s) for this service...
Service "xe" has 1 instance(s).
  Instance "xe", status READY, has 1 handler(s) for this service...
The command completed successfullyIn the above, remember the "xe" from 'Service "xe" has 1 instance(s).'. I expect to see something about that in the TNSNAMES.ORA file in your ORACLE_HOME\network\admin directory. That file should have an entry like
XE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = FCC003L)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
  )and you will note the XE on the left side of the equal sign (which is a network alias), and one XE in the (SERVICE_NAME = XE) line. On YOUR system, the XE should be replaced by whatever you called your database (often 'orcl'). REMEMBER THIS ALIAS;-) and also make note of the host that your entry uses. If your host name changes because of DHCP, you're hooped (for a while).
If the database is registered (shows up in the list), the next step is to make sure a userid is available. You could use 'system' (try to avoid using SYS since it is the master userid and if you mess that up, you mess up all your homework. In a production encvironment, every access to SYS will be audited.
So, let's create a userid called me with (in 11g case sensitive) password 'myself'. Make sure that user is allow to log in (create session) and create a table.
C:\temp>sqlplus system/oracle
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Feb 7 20:54:38 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
SQL> create user me identified by myself;
User created.
SQL> rem to show you how to change password ...
SQL> alter user me identified by myself account unlock;
User altered.
SQL> grant create session, create table to me;
Grant succeeded.
SQL> exit
Disconnected from Oracle Database 10g Express Edition Release 10.2.0.1.0 - Productionand now see whether we can log in using the same 'network' technique we will later use with SQLDeveloper.
Do you remember the XE discussion above? Replace XE with the one on the left of the equal sign - the system looks that up to find which service it wants to access.
C:\temp>sqlplus me/myself@XE
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Feb 7 20:58:26 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
SQL> select * from dual;
D
X
SQL> exit
Disconnected from Oracle Database 10g Express Edition Release 10.2.0.1.0 - ProductionIf the above worked, you should have no problem accessing the system using SQLDeveloper. You simply use the HOST, the PORT and the SID (alias) or service from the "lsnrctl status" output in the SQLDeveloper fields.
If it did not work, try dropping the "@XE" to see whether you can get in (using the bequeath connection) which is useful for troubleshooting but will not help with the traditional SQLDeveloper connection. If you get in without the @XE (or whatever your alias is) but not with it, most likely either your listener is not up or your firewall is blocking the access to the listener.