I Have Oracle rev 10g

[Lorayne]

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

[Patrick Wallek]

Are your listener.ora file, on the server, and tnsnames.ora file, on the client, configured correctly for whatever database and port you are trying to connect to?

[twang]

please list the content of tnsnames.ora.

[Hein van den Heuvel]

>> I Have Oracle rev 10g

Congratulations!
Do you have the books, or the software as well? Is it installed? On an HPUX box perhaps?
Do you have it for a long time, ot just now?

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

Correct.
That is indeed the text which goes with that message.

How can we help you with that?
What is the problem?

What that per-chance be an error error code being reported? From what client? To which intended servert? RAC?
Can you connect using other clients/methods?

Did the connection ever work?
Perhaps before you went to 10g?
Exactly what version of 10g? 10.2.x.y?

Oh and yes, as ihinted by others, the likely answer is impoper TNSnames or Listener.ora configuations, but let's first see a better question pretty please?

Good luck!
Hein.