问题
I recently deploy one web application in one of my development servers. I'm using oracle, asp.net and c#. When I run the application in the server everything works fine, but when I try to run the application outside of the server (using my pc, for example) i get this error:
ORA-12154: TNS:could not resolve the connect identifier specified
If i run the application in my pc with visual studio it works fine.
Oracle is installed in Server "A" and the application is in server "B". Server "A" is in one domain and server "B" is in other domain.My pc is in the same domain has Server "A".
In my pc I can find the file tnsname.ora in C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN, but in Server "B" i can´t find it anywhere
any idea? Thanks for the help.
回答1:
Guess: An oracle client is not installed on Server B.
If you do have an oracle client installed then you can still put a tnsnames file in any location (Such as a directory on a network share). In order to do this, set a TNS_ADMIN system variable (System Properties->Advanced->Environment Variables on XP) to the directory containing your tnsnames files.
For me for example I have a system variable: TNS_ADMIN - C:\oracle\ora92\network\ADMIN
回答2:
Have you tried this yet? (from http://ora-12154.ora-code.com/)
ORA-12154: TNS:could not resolve the connect identifier specified
Cause: A connection to a database or other service was requested using a connect identifier, and the connect identifier specified could not be resolved into a connect descriptor using one of the naming methods configured. For example, if the type of connect identifier used was a net service name then the net service name could not be found in a naming method repository, or the repository could not be located or reached.
Action:
- If you are using local naming (TNSNAMES.ORA file):
Make sure that "TNSNAMES" is listed as one of the values of the NAMES.DIRECTORY_PATH parameter in the Oracle Net profile (SQLNET.ORA)
Verify that a TNSNAMES.ORA file exists and is in the proper directory and is accessible.
Check that the net service name used as the connect identifier exists in the TNSNAMES.ORA file.
Make sure there are no syntax errors anywhere in the TNSNAMES.ORA file. Look for unmatched parentheses or stray characters. Errors in a TNSNAMES.ORA file may make it unusable.
If you are using directory naming:
Verify that "LDAP" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
Verify that the LDAP directory server is up and that it is accessible.
Verify that the net service name or database name used as the connect identifier is configured in the directory.
Verify that the default context being used is correct by specifying a fully qualified net service name or a full LDAP DN as the connect identifier
If you are using easy connect naming:
Verify that "EZCONNECT" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
Make sure the host, port and service name specified are correct.
Try enclosing the connect identifier in quote marks. See the Oracle Net Services Administrators Guide or the Oracle operating system specific guide for more information on naming.
回答3:
Resolving TNS errors can be a real pain. A few things to keep in mind.
Most development environments (like visual studio) keep their own copy of the TNS connection information, and do not use the TNSNAMES.ora file. The file where this information is kept does not have to be called TNSNAMES.ora, that's just the default name. Which may be the reason you can't find it on Server B.
If you have the oracle client software (or an oracle database) you can use tnsping to check if your TNSNAMES.ora file is configured correctly.
The most frequent problems with a TNSNAMES.ora file configuration are using the wrong service name and/or using the wrong host name. You may need to change the "ODB_A" to "ODB_A.WORLD" or vice versa, depending upon the SQLNET settings. For Oracle 10, the latter is the default SQLNET setting. For the latter, you need to use ping to see server "A", and know if you need to use "SERVERA" or "SERVERA.DOMIN.COM" or an IP address.
回答4:
Is ORACLE_HOME set on server B?
回答5:
It seems you need to install Oracle Client on "Server B" (the application server), and configure it's TNSNAMES.ORA file. This is required since otherwise, the running code will have no idea where to look for the database you use in the application (probably you're configured a data source in web.config or hard-coded something). Remember - you cannot access Oracle (easily) without Oracle Client.
回答6:
Had the same problem. Turns out the TNSNAMES.ORA in out deployment environment had a different ADDRESS_NAME and SID/SERVICE_NAME ,and the application was configured to use the SID - which caused the problem.
Your connection string must contain the ADDRESS_NAME and not the SID
回答7:
Possible Resolutions -
Verify that the TNSNAMES.ORA exists and is accessible.
Make sure that there are no syntax errors in TNSNAMES.ORA.
Verify that the connection string is correct.
Verify if there are any DNS issues.
If the problem is while connect to server using PL sql developer client.try to install SQL developer within Program File instead of Program Files(x86)'s
回答8:
Add the environment:
Variable Name: TNS_ADMIN
Variable Value: (YourDrive):\app\(UserName)\product\11.2.0\dbhome_1\NETWORK\ADMIN
回答9:
I had faced the similar issue. The below code was working in my system but was not working in another server even though I had added a tns entry in tnsnames.ora file.
con = new OracleConnection();
con.ConnectionString = "User Id=username;Password=password;Data Source=uit45";
con.Open(); // throws error here
After digging and digging, I found out the solution for this. We need to ignore the entry in tns file and can be given tns entry as connection string, which worked fine for me. Try the below code.
con = new OracleConnection("Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=db-uit45.xxx)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SID=uit45)));User Id=username;Password=password");
con.Open();
Note that you need to give the associated values, especially for HOST,PORT,SID,User Id and Password.
来源：https://stackoverflow.com/questions/162762/ora-12154-error