ORA-12154: TNS:could not resolve the connect identifier specified

Problem:

ORA-12154: TNS:could not resolve the connect identifier specified

Solution:

• add this line to /etc/hosts:
  127.0.0.1 localhost.localdomain localhost

• 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.