Oracleora-12514:tns: Listener currently does not recognize the requested service in the connection descriptor

Issue: Oracle installation is successful, can be used after a period of time, login error Oracleora-12514:tns: The listener does not currently recognize the service requested in the connection descriptor

Check the relevant documents, as well as the changes, you can log in normally, record the workaround as follows

Cause: This problem is caused by the lack of a sid_list descriptor for the listener, which is often encountered when configuring with NETCA.

Solution Ideas:

1. Start the database by restarting the service, and again the connection is still unable to connect to the server.

2, consider monitoring Listener.ora

You may not have to specify the service name for the listener in the Listener profile Listener.ora (which is not specified after installing oracle11g). Normally, as long as the database starts, the client connects to the database with no problems, but sometimes a ORA-12514 error occurs when a recurring startup is turned off.

This problem is caused by the lack of a sid_list descriptor for the listener, which is often encountered when configured with NETCA, Listener.ora examples such as
Under

Since no listener is specified in the Listener.ora, we can specify the instance name of the listener in the Listener.ora file (with the following Red section, specifying its own name) so that the problem should be connected.

# Listener.ora Network Configuration File:f:\app\shou\product\11.2.0\dbhome_1\network\admin\listener.ora
# Generated by Oracle configuration tools.

Sid_list_listener =
(Sid_list =
(Sid_desc =
(Sid_name = Clrextproc)
(Oracle_home = F:\app\shou\product\11.2.0\dbhome_1)
(program = Extproc)
(Envs = "Extproc_dlls=only:f:\app\shou\product\11.2.0\dbhome_1\bin\oraclr11.dll")
)
(Sid_desc =
(Global_dbname = orcl.20.32.106)
(Oracle_home = F:\app\shou\product\11.2.0\dbhome_1)
(Sid_name = ORCL)
)

)

LISTENER =
(Description_list =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC1521))
(ADDRESS = (PROTOCOL = TCP) (HOST = localhost) (PORT = 1521))
)
)

Adr_base_listener = F:\app\shou

Oracleora-12514:tns: Listener currently does not recognize the requested service in the connection descriptor