How do you fix error ORA 12154 TNS could not resolve connect identifier specified?

The Solution

  1. Make sure that “TNSNAMES” is listed as one of the values of the NAMES. DIRECTORY_PATH parameter in the Oracle Net profile (SQLNET.
  2. Verify that a TNSNAMES.
  3. Check that the net service name used as the connect identifier exists in the TNSNAMES.
  4. Make sure there are no syntax errors anywhere in the TNSNAMES.

How do I resolve TNS issue?

Below is a list of things that you can try to resolve this issue.

  1. Verify that the tnsnames.
  2. Check the sqlnet.ora file under ‘Admin’ folder in Oracle home [Dir:\app\product\11.1.0\client_1\network\admin] and ensure that we have TNSNames in NAMES.DIRECTORY_PATH.

What is TNS error?

Troubleshooting the TNS-12154 Error The TNS-12154 error is encountered when SQL*Net cannot find the alias specified for a connection in the TNSNAMES. ORA file or other naming adapter. Before attempting to resolve the problem, it may be helpful to have a print out or view of both the TNSNAMES. ORA file and the SQLNET.

How do I find Tnsnames Ora?

When finding the tnsnames. ora location in Windows, look for the TNS_ADMIN registry entry. If TNS_ADMIN is set then you should be able to use a network alias, not the full “(DESCRIPTION…” connect string. The TNS_ADMIN parameter tells Oracle clients where to find the tnsnames.

How do I connect to Oracle database?

To connect to Oracle Database from SQL Developer:

  1. Access the menu from which you can select SQL Developer:
  2. Select Oracle – ORACLE_HOME.
  3. Select Application Development.
  4. Select SQL Developer.
  5. In the navigation frame of the window, click Connections.
  6. In the Connections pane, click the icon New Connection.

How do I configure listener Ora?

To configure a protocol address for Oracle JServer in an Oracle8i database:

  1. Start Oracle Net Manager.
  2. In the navigator pane, expand Local > Listeners.
  3. Select a listener.
  4. From the list in the right pane, select Listening Locations.
  5. Click Add Address.
  6. Select the TCP/IP or TCP/IP with SSL protocol from the Protocol list.

What is could not resolve the connect identifier specified?

This is one of the most common Oracle errors and it is basically telling you that you are trying to connect to a database name that is unknown to the system. The most common cause are typos in your connection string or network configuration files.

What is TNS details in Oracle?

What is a TNS? It is an alias. Like a hostname is an alias for an IP address, a TNS is an alias for an OCI (Oracle Call Interface) connection string. This string identifies the database server and database instance to connect to.

How do I manually create Tnsnames Ora?


  1. FTP the following file from your Oracle server:
  2. Add the following lines:
  3. Replace the string yourhost in the line (HOST = yourhost ) with the name of your Oracle server.
  4. (optional) Replace the default port number 1521 in the line (PORT = 1521 ) with your required port number.
  5. Write and quit the file.

How do I create a TNS service name?


  1. Enter dbca at the Oracle command-line to start the Oracle Net Configuration Assistant tool.
  2. On the Welcome window, select Local Net Service Name configuration.
  3. Select Add.
  4. Enter WAREHOUS in the Service Name field.
  5. Select TCP as the network protocol to communicate with the Tivoli Data Warehouse database.

How do I connect to Oracle without a client?

Add the Oracle. DataAccess. dll to your project. Create the connection string as in the following sample….This tool is about connecting to the database server without installing the Oracle client.

  1. Download Oracle Data Access Components (ODAC) 11.2. 0.1.
  2. Copy OraOps11w.
  3. Copy oci.
  4. Copy the Oracle.

How do I fix ORA 12547 TNS lost contact when trying to connect to Oracle?


  1. Ensure the DB is up and running and you can connect locally AS SYSDBA to the database using Oracle binaries owner (usually oracle:oinstall Unix / Linux user). If it does not work, probably you encounter a different problem.
  2. Check privileges of an Oracle file on Unix / Linux host where database is running: