i'm trying to connect to my oracle server using a batch file, but while i try connecting i got the following error:
ORA-12154: TNS: could not resolve the connect identifier specified
I've already check the tnsnames.ora ad the identifier is spelled correctly; i've put in the environment's variable a new variable named TNS_ADMIN that point on my admin folder in the client section.
ty tnsname.ora is as following
ORCL_SRVDATIORIO12 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = myhost)(PORT = 1521))
)
(CONNECT_DATA =
(SID = ORCL)
(SERVER = DEDICATED)
)
)
If i try connecting to that server using SSMA for example, using the tnsnames mode (SID or the description name), connection will establish just fine; while running it in command line it return me the error.
Also if i try running
tnsping <my tnsname>
i'll get:
TNS Ping Utility for 32-bit Windows: Version 12.2.0.1.0 - Production on 03-GEN-2019 14:36:59
Copyright (c) 1997, 2016, Oracle. All rights reserved.
File di parametri utilizzati:
C:\app\client\user\product\12.2.0\client_1\network\admin\sqlnet.ora
TNS-03505: Impossible finding name
So i checked the sqlnet.ora file and the directory path seems fine to me:
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT, LDAP)
any suggestion?
EDIT: i solved by simply creating a new text file and copy past the previous contents in the new one.
you need to check tnsnames.ora. tnsnames.ora contains tns names and their connection declarations. You need to use appropriate tns name to connect your database.
tnsping <tns_name> //tns_name is needed to be defined in tnsnames.ora
in your case
tnsping ORCL_SRVDATIORIO12 10
need to return success message. if it does not, it means that your connection decriber is wrong. In which case, you need to talk with your DBA
In a Debian machine, I can use tnsping to identify a tnsname.
But I can not found any tnsnames.ora in this machine. (nothing in $ORACLE_HOME/network/admin/ )
So, how can I find the tns name config file used by tnsping command ?
Is there any command (similar with tnsping) to locate the tnsnames file?
UPDATE: tnsping command result:
Thanks in advance
There is no common location and different applications/drivers apply various search paths with different order and precedences.
Check following locations:
$ORACLE_HOME/network/admin/
Current directory of application
$TNS_ADMIN (where TNS_ADMIN is environment variable settings)
Just for completeness in case of Windows check also
Registry key HKLM\SOFTWARE\ORACLE\KEY_{ORACLE_HOME_NAME}\TNS_ADMIN (for 64 bit)
Registry key HKLM\SOFTWARE\Wow6432Node\ORACLE\KEY_{ORACLE_HOME_NAME}\TNS_ADMIN (for 32 bit)
.NET config file (i.e. machine.config and/or web.config)
In ideal case all of them should point to the same location, consider to create symbolic links if needed.
NB, maybe file tnsnames.ora simply does not exist. Create such file in location mentioned above.
You tell us the tnsping is working... At my place the tnsping tool gives the exact location of the sqlnet.ora it is using.... The tnsnames.ora should be in the same directory.
When your environment is correctly configured the tnsnames should be in the mentioned directory. When it does not exist you could try running the netca command and configure "Naming Methods configuration" and add a destination with "Locale Net Service Name configuration". This utility will create sqlnet.ora en tnsnames.ora in the default location.
[oracle#somedir]$ tnsping test
TNS Ping Utility for Linux: Version 11.2.0.3.0 - Production on 27-JUL-2016 22:00:24
Copyright (c) 1997, 2011, Oracle. All rights reserved.
Used parameter files:
/home/oracle/app/oracle/product/11.2.3/dbhome_1/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = TEST)))
OK (0 msec)
I have installed oracleXE in my local meachine.
I have changed the services of Oracle level Automatic to Manual.
Know when i start the Oracle Services all are getting started except the OracleXNTNSListener service.
It saying some times below mentioned 1 error or 2 error
1>Windows could not start OracleXETNSListner service on Local Computer.
Error 1067:The process terminated unexpectedly.
OR
2>The OracleXNTNSListener service on Local Computer startred and then stopped.Some services stop automatically if they are not in use by other services or programs.
After some trials the listener got started.
What I did is for this, I have edited the listener.ora file.
In this line intialy HOST = hostname was there, I changed that to localhost ip i.e 127.0.0.1
(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
I know its a very old thread but, changing 127.0.0.1 to localhost in both listener.ora and tnsnames.ora helped me.
My listener.ora file was like this
(ADDRESS = (PROTOCOL = TCP)(HOST = my_computer_name)(PORT = 1521))
I changed to
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
and then it worked.
I face this problem, because I have installed Oracle 12c previous, then I try to install Oracle 11g express.
Check this registry key to ensure ORACLE_HOME is configured for the service:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ORACLE\KEY_XE\ORACLE_HOME
If that doesn't exist, check here:
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_XE\ORACLE_HOME
Also make sure this other key isn't pointing to your old client registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ORACLE\KEY_XE\ORACLE_HOME_KEY
or
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_XE\ORACLE_HOME_KEY
Check if the system variable ORACLE_HOME is set to C:\oraclexe\app\oracle\product\11.2.0\server (or similar).
this might be caused because you changed your PC-NAME. Make sure in "listener.ora" file HOST = PC-NAME (eg: admin-PC).
We have an application running locally where we're experiencing the following error:
ORA-12514: TNS:listener does not currently know of service requested
in connect descriptor
I've tested the connection using TNSPing which resolved correctly and
I tried SQLPlus to try connecting, which failed with the same error as above. I used this syntax for SQLPlus:
sqlplus username/password#addressname[or host name]
We have verified that:
the TNS Listener on the server is running.
Oracle itself on the server is running.
We don't know of any changes that were made to this environment.
Anything else we can test?
I had this issue and the fix was to make sure in tnsnames.ora the SERVICE_NAME is a valid service name in your database. To find out valid service names, you can use the following query in oracle:
select value from v$parameter where name='service_names'
Once I updated tnsnames.ora to:
TEST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = *<validhost>*)(PORT = *<validport>*))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = *<servicenamefromDB>*)
)
)
then I ran:
sqlplus user#TEST
Success!
The listener is basically telling you that whatever service_name you are using isn't a valid service according to the DB.
(*I was running sqlplus from Win7 client workstation to remote DB and blame the DBAs ;) *)
I know this is an old question, but still unanswered. It took me a day of research, but I found the simplest solution, at least in my case (Oracle 11.2 on Windows 2008 R2) and wanted to share.
The error, if looked at directly, indicates that the listener does not recognize the service name. But where does it keep service names? In %ORACLE_HOME%\NETWORK\ADMIN\listener.ora
The "SID_LIST" is just that, a list of SIDs and service names paired up in a format you can copy or lookup.
I added the problem Service Name, then in Windows "Services" control panel, I did a "Restart" on the Oracle listener service. Now all is well.
For example, your listener.ora file might initially look like:
# listener.ora Network Configuration File: C:\app\oracle_user\product\12.1.0\dbhome_1\network\admin\listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\app\oracle_user\product\12.1.0\dbhome_1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\app\oracle_user\product\12.1.0\dbhome_1\bin\oraclr12.dll")
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
... And to make it recognize a service name of orcl, you might change it to:
# listener.ora Network Configuration File: C:\app\oracle_user\product\12.1.0\dbhome_1\network\admin\listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\app\oracle_user\product\12.1.0\dbhome_1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\app\oracle_user\product\12.1.0\dbhome_1\bin\oraclr12.dll")
)
(SID_DESC =
(GLOBAL_DBNAME = orcl)
(ORACLE_HOME = C:\app\oracle_user\product\12.1.0\dbhome_1)
(SID_NAME = orcl)
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
In my circumstances the error was due to the fact the listener did not have the db's service registered. I solved this by registering the services. Example:
My descriptor in tnsnames.ora:
LOCALDB =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = LOCALDB)
)
)
So, I proceed to register the service in the listener.ora manually:
SID_LIST_LISTENER =
(SID_DESC =
(GLOBAL_DBNAME = LOCALDB)
(ORACLE_HOME = C:\Oracle\product\11.2.0\dbhome_1)
(SID_NAME = LOCALDB)
)
Finally, restart the listener by command:
> lsnrctl stop
> lsnrctl start
Done!
I had this issue at Windows server 2008 R2 and Oracle 11g
go to Net Manager > Listener > select database services form the combox > "Global Database Name" must be same as "SID" and "Oracle Home Directory" must be correct.
If you don't have any entry for database services, create one and set correct global database , sid and oracle home.
This really should be a comment to [Brad Rippe][1]'s answer, but alas, not enough rep. That answer got me 90% of the way there. In my case, the installation and configuration of the databases put entries in the tnsnames.ora file for the databases I was running. First, I was able to connect to the database by setting the environment variables (Windows):
set ORACLE_SID=mydatabase
set ORACLE_HOME=C:\Oracle\product\11.2.0\dbhome_1
and then connecting using
sqlplus / as sysdba
Next, running the command from Brad Rippe's answer:
select value from v$parameter where name='service_names';
showed that the names didn't match exactly. The entries as created using Oracle's Database Configuration Assistant were originally:
MYDATABASE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = mylaptop.mydomain.com)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = mydatabase.mydomain.com)
)
)
The service name from the query was just mydatabase rather than mydatabase.mydomain.com. I edited the tnsnames.ora file to just the base name without the domain portion so they looked like this:
MYDATABASE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = mylaptop.mydomain.com)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = mydatabase)
)
)
I restarted the TNS Listener service (I often use lsnrctl stop and lsnrctl start from an administrator command window [or Windows Powershell] instead of the Services control panel, but both work.) After that, I was able to connect.
[1]: https://stackoverflow.com/users/979521/brad-rippe
Starting the OracleServiceXXX from the services.msc worked for me in Windows.
For thoses Who are using spring-boot and jdbc for connection.
You have to be careful while writing jdbcUrl in application.properties
With SID in Database connection -
source.datasource.jdbcUrl = jdbc:oracle:thin:#[HOST][:PORT]:SID
With Service name in db connection
globe.datasource.jdbcUrl = jdbc:oracle:thin:#//[HOST][:PORT]/SERVICE
This worked for me :)
For Dbeaver users: try selecting "SID" instead of "Service name" in connection settings.
I had the same problem. For me, just writing
sqlplus myusername/mypassword#localhost
did the trick, doing so makes it connect to the default service name, I guess.
This error can occur when an application makes a new connection for every database interaction or the connections are not closed properly. One of the free tools to monitor and confirm this is Oracle Sql developer (although this is not the only tool you can use to monitor DB sessions).
you can download the tool from oracle site Sql Developer
here is a screenshot of how to monitor you sessions. (if you see many sessions piling up for your application user during when you see the ORA-12514 error then it's a good indication that you may have connection pool problem).
Check to see the database is up. Log onto the server, set the ORACLE_SID environment variable to your database SID, and run SQL*Plus as a local connection.
I resolved this issue in my linux enviroment updating the IP of my machine in /etc/hosts file.
You can verify your network IP (inet end.) with:
$ifconfig
See if your IP matches with /etc/hosts file:
$cat /etc/hosts
Edit your /etc/hosts file, if nedded:
$sudo gedit /etc/hosts
Bye.
what worked for me was really simple, I just needed to initiate the service manually in the "Windows Services" (services.msc in cmd trompt).
my service name is: OracleServiceXXXXX.
I had also faced the same problem and spent 3 days to dig it out.
This happens because of your wrong TNS service entry.
First check whether you are able to connect to standby database from primary database using sql > sqlplus sys#orastand as sysdba (orastand is a standby database).
If you are not able to connect then it is a problem with the service. Correct the entry of service name in TNS file at primary end.
Check standby database the same way. Make the changes here too if required.
Make sure the log_archive_dest_2 parameter has the correct service name.
For those that may be running Oracle in a VM (like me) I saw this issue because my VM was running out of memory, which seems to have prevented OracleDB from starting up/running correctly. Increasing my VM memory and restarting fixed the issue.
Lots of answers here, but here comes a working example with code that you can copy and paste and test immediately:
For me the error 12514 was solved after specifying the correct SERVICE_NAME.
You find that on the server in the file tnsnames.ora which comes with 3 predefined service names (one of them is "XE").
I installed the Oracle Express database OracleXE112 which already comes with some preinstalled demo tables.
When you start the installer you are asked for a password. I entered "xxx" as password. (not used in production)
My server runs on the machine 192.168.1.158
On the server you must explicitely allow access for the process TNSLSNR.exe in the Windows Firewall. This process listens on port 1521.
OPTION A: For C# (.NET2 or .NET4) you can download ODAC11, from which you have to add Oracle.DataAccess.dll to your project. Additionally this DLL depends on: OraOps11w.dll, oci.dll, oraociei11.dll (130MB!), msvcr80.dll.
These DLLs must be in the same directory as the EXE or you must specify the DLL path in: HKEY_LOCAL_MACHINE\SOFTWARE\Oracle\ODP.NET\4.112.4.0\DllPath. On 64 bit machines write additionally to HKLM\SOFTWARE\Wow6432Node\Oracle\...
OPTION B: If you have downloaded ODAC12 you need Oracle.DataAccess.dll, OraOps12w.dll, oci.dll, oraociei12.dll (160MB!), oraons.dll, msvcr100.dll. The Registry path is HKEY_LOCAL_MACHINE\SOFTWARE\Oracle\ODP.NET\4.121.2.0\DllPath
OPTION C: If you don't want huge DLL's of more than 100 MB you should download ODP.NET_Managed12.x.x.x.xxxxx.zip in which you find Oracle.ManagedDataAccess.dll which is only 4 MB and is a pure managed DLL which works in 32 bit and 64 bit processes as well and depends on no other DLL and does not require any registry entries.
The following C# code works for me without any configuration on the server side (just the default installation):
using Oracle.DataAccess.Client;
or
using Oracle.ManagedDataAccess.Client;
....
string oradb = "Data Source=(DESCRIPTION="
+ "(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.158)(PORT=1521)))"
+ "(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=XE)));"
+ "User Id=SYSTEM;Password=xxx;";
using (OracleConnection conn = new OracleConnection(oradb))
{
conn.Open();
using (OracleCommand cmd = new OracleCommand())
{
cmd.Connection = conn;
cmd.CommandText = "select TABLESPACE_NAME from DBA_DATA_FILES";
using (OracleDataReader dr = cmd.ExecuteReader())
{
while (dr.Read())
{
listBox.Items.Add(dr["TABLESPACE_NAME"]);
}
}
}
}
If the SERVICE_NAME=XE is wrong you get error 12514. The SERVICE_NAME is optional. You can also leave it away.
In my case the database had ran out of disk space. Which caused it to not respond. Once I cleared up that issue everything worked again.
I got the same error because the remote SID specified was wrong:
> sqlplus $DATASOURCE_USERNAME/$DATASOURCE_PASSWORD#$DB_SERVER_URL/$REMOTE_SID
I queried the system database:
select * from global_name;
and found my remote SID ("XE").
Then I could connect without any problem.
In my case, round brackets around the SERVICE_NAME was missing in the tnsnames.ora file.
<DBNAME> =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL=TCP)(HOST = nupark-cnvr-ora )(PORT=1521))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = <DBNAME> ***CLOSING ROUND BRACKET WAS MISSING HERE***
)
)
LISTENER_<DBNAME> =
(ADDRESS = (PROTOCOL = TCP)(HOST = nupark-cnvr-ora)(PORT = 1521))
I had just to replace my connection string
from:
jdbc:oracle:thin:#localhost:1521:xe
To:
jdbc:oracle:thin:#localhost:1521:orcl
For me this was caused by using a dynamic ipadress using installation. I reinstalled Oracle using a static ipadress and then everything was fine
Restarting the VM worked for me
My issue was resolved by replacing the'SID' in URL with 'service name' and correct host.
tnslsnr is up but database is down.
For oracle novice it is not obvious that database may be down while connections are accepted.
I had to start up database manually like that
su - oracle
export ORACLE_SID=XE
sqlplus sys as sysdba
And then in sql console
startup
In my case i failed to startup but got another error message and found the source of a problem - i had to change host name and then database auto startup was functional again.
I have implemented below workaround to resolve this issue.
I have set the ORACLE_HOME using command prompt
(right click cmd.exe and Run as System administrator).
Used below command
set oracle_home="path to the oracle home"
Go to All programs --> Oracle -ora home1 --> Configuration migration tools --> Net Manager --> Listener
Select Database Services from dropdown.
Both Global database name and SID are set to the same (ORCL in my case).
Set Oracle Home Directory.
Oracle Net Manager window example from oracle documentation:
Click on File and save network configuration.
The problem was that my connection string url contained database name instead of SID.
Replacing database name with oracle database connection SID solved this problem.
To know your oracle SID's you can browse tnsnames.ora file.
XE was the actual SID, so this is how my tomcat connection string looks like now:
<Resource
name="jdbc/my_db_conn"
auth="Container"
type="javax.sql.DataSource"
driverClassName="oracle.jdbc.driver.OracleDriver"
url="jdbc:oracle:thin:#//127.0.0.1:1521/XE"
username="test_user"
password="test" />
My server version was "Oracle 11.2 Express", but solution should work on other versions too.
I had a case that I used DBMS where I had to fulfill a db connection form.
I put SID into the Database field and in the dropdown, next to the field, I had had 'Service Name' value instead of 'SID' value.
(normally I don't use Oracle database so I've not been aware of the difference)
That was the reason I got the error message.
The problem can be in the incorrect URL.
For example, I'm using Oracle database (inside VM) with Spring framework and having this issue.
I had in my application.properties file:
spring.datasource.url=jdbc:oracle:thin:#//localhost:1521/orcl12c
But the db version was defferent:
spring.datasource.url=jdbc:oracle:thin:#//localhost:1521/orclcdb
The correct URL can be found in the tnsnames.ora file (this file would be available where the Oracle server, so if you using VM, you should look for this file inside your host VM).
For example for Oracle in the VirtualBox the command to see this file is:
nano /u01/app/oracle/product/version/db_1/network/admin/tnsnames.ora
In my case for Linux environment, the oracle file at ORACLE_HOME/bin was highlighted in "Red" color with different permissions as below:
I changed the permissions of this file as below:
1) Stop Oracle -> sudo systemctl stop oracle.service
2) Change the permission of oracle file at ORACLE_HOME/bin directory as "sudo chmod 777 oracle"
3) Start Oracle -> sudo systemctl start oracle.service
Then after this change, I checked the status of listener using lsnrctl status.Here, I can see the db instances loaded successfully.
However, I can connect using sqldeveloper only, with sqlplus command line I'm getting ORA-12547: TNS Lost Contact error. So, this can a quick workaround to use sqldeveloper.
Note: Take a backup of oracle file before changing the permissions.
I'm trying to connect to an oracle db from an ASP classic application, however I keep running into the ORA-12154 error.
TNSNAMES.ORA is configured properly
DBSOURCE.A.B.com =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = C.D.B.com)(PORT = 1231))
)
(CONNECT_DATA =
(SERVICE_NAME = DBSOURCE)
)
)
I can TNSPING
C:\Documents and Settings\USERID.A>tnsping DBSOURCE
TNS Ping Utility for 32-bit Windows: Version 10.2.0.4.0 - Production on 09-MAR-2
011 09:12:31
Copyright (c) 1997, 2007, Oracle. All rights reserved.
Used parameter files:
C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)
(HOST = C.D.B.com)(PORT = 1231))) (CONNECT_DATA = (SERVIC
E_NAME = DBSOURCE)))
OK (30 msec)
I can create an ODBC connection and I've tested the connection which is successful.
I can connect to the oracle db through toad.
I've checked my sqlnet.ora file
NAMES.DEFAULT_DOMAIN = A.B.com
SQLNET.AUTHENTICATION_SERVICES= (NONE)
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
I've also checked that the TNSNAMES.ORA as one of my system paths.
I can connect to the DB with SQLPLUS
Here is the code that throws the error
dim CnnStr
Set Cnn = Server.CreateObject("ADODB.Connection")
CnnStr="Provider=MSDAORA.1;Password=pass;User ID=user;Data Source=DBSOURCE"
Cnn.Open CnnStr
I am running windows XP Pro 32bit SP3
I've tested this on a co-workers machine and the asp app has no issues, am I missing a configuration somewhere or did I mess up my config?
Thanks for the help everyone!
It seems all the settings have been checked but here is my suggestions for some trouble shooting:
How about restrictions on the account IIS is running under? Does it have the file permissions to read the TNSNAMES? Have you tried to give the user more rights. Even run IIS with Local As System Account? Remember to put it back the way it was.
You are sure there is not 3rd party app such anti virus or firewall that could influence / block access. (Disable them to test but do not forget to re-enable :)
(What did you finally do to solve it?)
"this works on a co-worker machine but
not mine."
ORA-12154 is usually a configuration issue, and it would certainly seem to be so in your case. The short answer is to compare your machine with your colleague's one and figure out what the difference is.
Things to check include:
the TNANAMES.ORA file
the SQLNET.ORA file
the LISTENER.ORA file (if you're using a local database)
Do you have multiple Oracle homes? Check that IIS doesn't point to the other ORA_HOME (and thereby not finding your tnsnames.ora entry).
I'm not very familiar with IIS configuration, so I would test this by adding the TNS entry to all tnsnames.ora on my PC.
If you are running a 64-bit OS and oracle 10 try installing all the patches for oracle.
Something similar happened to me, SQL plus and all else worked, except my .NET program.
I was running a .Net program out of the "Program files (x86)" folder. Installing patches fixed it.
The likely problem is the lack of read permission upon the Oracle directories by the User IIS is running-as.
As #Derick says, temporarily set the permissions wide-open on the $ORACLE_HOME directory (Everyone = Full Control), restart IIS, and test. When that works, give the IIS User read permission against that directory.
You can also confirm this issue using Process Monitor from Microsoft SysInternals, and seeing the failure message during the CreateFile(...) API call to open the DLLs or read the TNSNAMES.ORA file. Given the way temporary files work when selecting through cursors, you may also need to give the IIS user write permissions into some directories.
Try setting the value of the environment variable TNS_ADMIN on the machine with the problem to /network/admin (or wherever your tnsnames.ora file lives) and see if that helps.
I had the similar problem and found a simple solution. You don't have to modify any config files. Hope this can help you:
CREATE DATABASE LINK server2_db
CONNECT TO dbuser IDENTIFIED BY pwd USING
'(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = server_2)(PORT = port_num))
)
(CONNECT_DATA =
(SERVICE_NAME = server2_db)
)
)';
The solution is from here:http://oraclequirks.blogspot.com/2008/11/ora-12154-tnscould-not-resolve-service.html