Oracle ORA-12154: TNS: Could not resolve service n

Question

I am a SQL Server user .

I am on a project that is using oracle (which I rarely use) I need to create an ODBC connection so I can access the some data via MS Access I have a application on my machine called oraHome90. It seems to allow a configuration of something called a listener in a “net configuration utility”, I think that a “Local Net Service Name Configuration” needs to also be done. The IT support gave me this information to set up the ODBC connection . I have tried every combination that I can think of. I can get past a test that successfully passes a test to “login“ to the oracle server database. When I try to create the ODBC connection I get the following error: ORA-12154: TNS: Could not resolve service name.

Assuming that I want to start from scratch and the following information is supposed to allow for me to connect to the database….. Any suggestions or comment ? Note: ultimately the project will have a website .ASP page query the data, but I have to first prove that I can see the data using the ODBC connection via MS Access

Service name: SERVICENAME
HOST = HOST.XYZi.com
User Id: MYUSERID
Password: MYPASSWORD
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

'Oracle Connection
Dim ocst
Dim oconn

ocst = "Provider=OraOLEDB.Oracle;" & _ 
        "Data Source=DATASOURCE;" & _ 
        "User ID=CHIJXL;" & _ 
        "Password=password;" 

set oconn = CreateObject("ADODB.Connection")

Answer 1

I struggled to resolve this problem for hours until I found an Environment variable called TNS_ADMIN set in My Computer => Properties => Advanced => Environment Variables => look in System variables for an entry called TNS_ADMIN. TNS_ADMIN is added to change the default path for Tnsnames.ora entry. This is useful when its used in a network environment where a generic tnsnames.ora entry can be setup for all the network computers. To look at the default path of tnsnames.ora add the default path in TNS_ADMIN.

Answer 2

I experienced this problem too. I discovered the problem is because Oracle DB does not like the space in C:program files (x86)\Toad...... so I created a new directory named C:App\Toad then reinstalled in it to connect Toad to Oracle. It worked.

Answer 3

This was mentioned in a comment to another answer, but I wanted to move it to an actual answer since this was also the problem in my case and I would have upvoted it if it had been an answer.

I'm on Linux and the tnsnames.ora file was not set to readable by everyone. After making it readable connecting via tns locally worked.

$ chmod +r tnsnames.ora

Answer 4

In reference to #7 in this MSDN POST , adding a registry entry worked for me. I had Vs2010, et oracle 11.0 installed.

Check for the registry key “TNS_ADMIN” at HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE. If it exists then make sure it has the right value as “Dir:\app\product\11.1.0\client_1\network\admin”. If you don’t see the key then create the key and set appropriate value as below. Regedit->HKEY_LOCAL_MACHINE->Software->Oracle->RightClick NEW->StringValue and name it TNS_ADMIN and give the value “X:\app\product\11.1.0\client_1\network\admin”

Answer 5

Going on the assumption you're using TNSNAMES naming, here's a couple of things to do:

• Create/modify the tnsnames.ora file in the network/admin subdirectory associated with OraHome90 to include an entry for your oracle database:

> SERVICENAME_alias =
>    (DESCRIPTION =
>     (ADDRESS = (PROTOCOL = TCP)(HOST = HOST.XYZi.com)(PORT = 1521))
>     (CONNECT_DATA = (SERVICE_NAME = SERVICENAME))

This is assuming you're using the standard Oracle port of 1521. Note that servicename_alias can be any name you want to use on the local system. You may also find that you need to specify (SID = SERVICENAME) instead of (SERVICENAME=SERVICENAME).

• Execute tnsping servicename_alias to verify connectivity. Get this working before going any further. This will tell you if you're past the 12154 error.
• Assuming a good connection, create an ODBC DSN using the control panel, specifying the ODBC driver for Oracle of your choice (generally there's a Microsoft ODBC driver at least, and it should work adequately as a proof of concept). I'll assume the name you gave of DATASOURCE. Use the servicename_alias as the Server name in the ODBC configuration.
• At this point you should be able to connect to your database via Access. I am not a VB programmer, but I know you should be able to go to File->Get External Data->Link Tables and connect to your ODBC source. I would assume your code would work as well.

Answer 6

It has nothing to do with a space embedded in the folder structure.

I had the same problem. But when I created an environmental variable (defined both at the system- and user-level) called TNS_HOME and made it to point to the folder where TNSNAMES.ORA existed, the problem was resolved. Voila!

venki