ORA-12154 Error

Question

Hi there,
I am having a problem connecting to a database that we have just created on a new server. The connection is fine using SQL*PLus, Enterprise Manager or SQL Developer, but we have an application that connects to this database sitting on the same server and this returns the error listed above. The username / pwd etc are all correct in the config file, and is a .NET app, but I cannot understand why it won't connect. I am using the standard oracle client (Oracle.Client) in .NET, the only real difference is that I am running the software on a x64 OS, could this be causing a problem?
Many thanks for any help that you might be able to provide
Dan

Answer 1

Hi Dan,
It sounds like the local sqlnet.ora or listener.ora file is wrong . . .
The ORA-12154 is a very common error, always related to your local copy of the tnsnames.ora file, your listener configuration and your database name aliases.
Make sure that your listener is listening for the same service name that you are using.
Your service name might have an alias, so check for global (world) entries and local entries. Check $ORACLE_HOME/network/admin/tnsnames.ora.
Check your global_name setting with this SQL:
select * from global_name;
The query value should match your init.ora parms for db_name and db_domain, You can change the global_name with an alter database commend, as follows:
alter database rename global_name to xxx;
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.