Oracle error codes


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

This is an Oracle Database Server Message. This can be generated by the Oracle Database when running any Oracle program.

What is the cause of ORA-12154 from Oracle 11g ?

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.

How to fix ORA-12154 from Oracle 11g ?

This is in general the very first error message you get when you try to establish a connection to your oracle database. Often, it's a typographical error in your connexion string or in your tnsnames.ora file.

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 (general tnsnames.ora location is: $ORACLE_HOME/network/admin/tnsnames.ora).

- 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.

How to solve ORA-12154 ?

How to deepen your knowledge about Oracle?

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Contacting Oracle support services ?

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