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.
- If you are using local naming (TNSNAMES.ORA file):
o Make sure that "TNSNAMES" is listed as one of the values of the NAMES.DIRECTORY_PATH parameter in the Oracle Net profile (SQLNET.ORA)
o Verify that a TNSNAMES.ORA file exists and is in the proper directory and is accessible.
o Check that the net service name used as the connect identifier exists in the TNSNAMES.ORA file.
o 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:
o Verify that "LDAP" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
o Verify that the LDAP directory server is up and that it is accessible.
o Verify that the net service name or database name used as the connect identifier is configured in the directory.
o 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:
o Verify that "EZCONNECT" is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).
o Make sure the host, port and service name specified are correct.
o 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.
This Oracle error ORA-12154 is thrown during the logon process to a database. This ORA-12154 error indicates that the communication software in Oracle ( SQL *Net ) did not recognize the host/service name specified in the connection parameters.
For a database name to be recognized, it must be resolved by Oracle Client. To resolve a name, Oracle client uses either a TNSNames.ora, A Directory Server or an Oracle Names Server.
ORA-12154: TNS:could not resolve service name - ORA-12154 Error / Oracle Error
If the cause for this Oracle error is Oracle Net could not locate the net service name specified in the
tnsnames.ora configuration file the perform the following steps to resolve this ora error / tns error:
· Verify that a
tnsnames.ora file exists.
· Verify that there are not multiple copies of the
· In the
tnsnames.ora file, verify that the net service name specified in your connect string is mapped to a connect descriptor.
· Verify that there are no duplicate copies of the
· If you are using domain names, verify that your
sqlnet.ora file contains a
NAMES.DEFAULT_DOMAIN parameter. If this parameter does not exist, you must specify the domain name in your connect string.
· If you are not using domain names, and this parameter exists, delete it or disable it by commenting it out.
· If you are connecting from a login dialog box, verify that you are not placing an "@" symbol before your connect net service name.
· Activate client tracing and repeat the operation.
If the cause for the ORA-12514 Oracle error is " Oracle Net could not locate the database service name or net service name specified in the directory server" then perform the following steps for resolving this ora error or tns error:
· Verify that the database service or net service name entry exists in the directory that this computer was configured to use.
· Verify that the
sqlnet.ora file includes the following entry:
· NAMES.DIRECTORY_PATH=(ldap, other_naming_methods)