Ora-12541:tns: No listening program

Ora-12541:tns when connecting to Oracle with PL/SQL Developer: No listener error, as shown in the following figure:

　　How to initiate the monitoring of Oracle .

1. Open Net Configuration Assistant

2. Select Listener Configuration, Next

3. Select Reconfigure, Next

4. Select Listener, Default, Next

Note: If your listener is started, a prompt box appears and the option is

5. Select the protocol, use the default TCP protocol, and next

6. Select port number, use standard port number 1521, next

7. Do not configure another listener, select No, Next

8. Listener configuration Complete, next

Re-service name, test connection

1. Select NET Server configuration, Next

2. Select Reconfigure, Next

3. Select Database name, next

4. Fill in the service name, that is, you create the database when the full database name, next

5. Select the TCP protocol and next

6. Fill in the host name (you can fill in your IP address, you can also fill in your host name), using the standard port number 1521, next

7. For testing, the next step

8. Select Change Login

9. Fill in user name and password, determine

10. Test connection success, next

11. Network SERVICE name, default (same as previous database name), next

12. Do not configure another net service name, choose No, Next

13.Net Service name configuration completed, Next, complete

Start Pl/sqldeveloper, enter username and password, login successful