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Re: Failed to connect to Oracle DB.

 
KennyC
Advisor

Failed to connect to Oracle DB.

Hi all experts,

I had a problem with the connections to Oracle DBs. The Oracle DB is installed in NT 4.0 server. The workstations (Win 98/Win 95) can login to the NT server and have read/write access to the directories contain the DB. Some workstations in the same network can login to the Oracle DBs but some can't. It prompted "Failed to connect to DB" while login. As checked, there is no Oracle client installed on the workstations. Only a shortcut to run the login from the folders which mapped from the server. Do you have any ideas how to solve this problem?

Thanks very much in advance.
Kenny.
8 REPLIES 8
Ganesh Babu
Honored Contributor

Re: Failed to connect to Oracle DB.

hi,
is the users asked a loginid & pwd and then it fails or once they open the shortcut which is mapped from teh server gives the error??

Ganesh
KennyC
Advisor

Re: Failed to connect to Oracle DB.

Hi Ganesh,

The users can open the shortcut and prompt for login. But when we type the the ID and pwd, it promted that error message. Do you have any ideas about this?

Thanks for your help.
Kenny.
Ganesh Babu
Honored Contributor

Re: Failed to connect to Oracle DB.

Hi Kenny,
Usually oracle client will have a file named init.ora which has the information about the server name / ip address & the port to connect..

so check whether that file is there in the server share / in the client machine itself(may be u can check how it is there in the clients which are able to connect also..)

if both the client who is able to connect & not able to connect have the file in the same location..

then try ping from client to the server using the machine name & once again using the ip address..

then try telnet

by doing this test u should be able to figure out where is the issue..

Ganesh
Jon Finley
Honored Contributor

Re: Failed to connect to Oracle DB.

Are the workstations all the same OS?

Do they all have the same software installed?

What is the exact error message when they fail to connect?

Server error message/workstation error message from Event Viewer.

Jon
"Do or do not. There is no try!" - Yoda
Indira Aramandla
Honored Contributor

Re: Failed to connect to Oracle DB.

Hi Kenny,

What is the Oracle error message :-
Like ORA-12154: TNS:could not resolve service name OR something like that.

From your workstation can you ping to the server/workstation where the database is runing. If so can you tnsping as well.

This will work if the tnsnames.ora file located at $TNS_ADMIN directory will have the hostname, database name (SID_NAME)and the port number. If this is configured fien you should successfully tnsping with the name that you specified in the tnsnames.ora file.

Otherwise the error could be something to do with the wrong username or password.

if you provide the correct ORA error message then we can follow form there.


Indira A
Never give up, Keep Trying
KennyC
Advisor

Re: Failed to connect to Oracle DB.

Thanks all experts, I had checked that the init.ora file and the client workstations can access that file. I also checked with the workstations that all have create the DB Alias to the DB. TNS ping also can ping the DB instance. However, when I opened the application and login, it prompted the error message "Failed to connect to DB" immediately and seems that there is no verification for the ID and pw.
All the workstations are running Win 95 with the same "Oracle for windows" running.
Do you have any idea how to solve the problem?

Thanks.
Kenny.
Jon Finley
Honored Contributor

Re: Failed to connect to Oracle DB.

Ok... I'm confused. You stated that there is NOT an Oracle client install on the Workstations, then you state: "TNS ping also can ping the DB instance." and "All the workstations are running Win 95 with the same "Oracle for windows" running."

That sounds like a client install was done on each workstation.

Also... What does "create the DB Alias to the DB." mean? Where are you creating this alias?

If you can use tnsping to ping the Oracle instance from each workstation, then you should be able to connect.

Jon
"Do or do not. There is no try!" - Yoda
KennyC
Advisor

Re: Failed to connect to Oracle DB.

Thanks all experts. Sorry that I had been misleaded by my colleagues. Actually the workstations had installed Oracle for windows. So they can TNSping the instance. In fact, we find out that the problem may from some DLL files. We had re-installed the application and finally can connect to the DBs and the problem had been solved.

Thanks very much for your kindness help.

Kenny.