This discussion is archived
2 Replies Latest reply: Apr 15, 2013 10:16 AM by Chandrakaanth Ramamurthy RSS

ORA-12505, TNS:listener and ORA-12514: TNS:listener

S10390 Journeyer
Currently Being Moderated
Hi All,

Am not able to connect to the database through the SQL Developer. When i am trying to connect the error was as below.

"An error was encountered performing the requested operation:

Listener refused the connection with the following error:
ORA-12505, TNS:listener does not currently know of SID given in connect descriptor

Vendor code 12505"

My Database version : Oracle Database 10g Express Edition
O/S : Windows 7, 32 bit

I have tried to restart the machine and also the OraclceServiceXE service in the services menu, but of no use.

And when i am trying to connect it from the sqlplus prompt...the error was

"C:\>sqlplus santhu/abcd@xe

SQL*Plus: Release - Production on Sun Apr 7 14:30:21 2013

Copyright (c) 1982, 2005, Oracle. All rights reserved.

ORA-12514: TNS:listener does not currently know of service requested in connect

Could you please help me where to check for the resolution.

  • 1. Re: ORA-12505, TNS:listener and ORA-12514: TNS:listener
    Jim Smith Expert
    Currently Being Moderated
    If you installed Express edition, your sid or service should be XE, so this error implies the database isn't up.

    Open a command window and type
    lsnrctl status.   
    This should show what services are running (if any).

    tnsping xe
    This will show the connection definition being used. It is what you would expect? Are host, port and sid or service correct?
    Do they match what you have entered for your connection definition in SQL Developer?

    If the definitions seem OK, try using the start menu options to stop and start the XE database and try connectiing again.
  • 2. Re: ORA-12505, TNS:listener and ORA-12514: TNS:listener
    Chandrakaanth Ramamurthy Explorer
    Currently Being Moderated
    Just try following the below steps

    1. Check if the ORACLE_HOME and TNS_ADMIN variables are set properly(any change would require a restart).

    2. Check if the correct driver is installed.

    3. tnsping any SID and see if there is a response.

    4. Check if the file TNSNAMES.ORA and SQLNET.ORA are in the correct location with the correct entries

    This should resolve the issue


  • Correct Answers - 10 points
  • Helpful Answers - 5 points