About Oracle "ORA-12514 TNS Listener does not currently recognize request service in connection descriptor" error

About Oracle "ORA-12514 TNS Listener does not currently recognize request service in connection descriptor" error
Reason:
The listener server name is not specified in Listener.ora.

Here's how to solve the idea:

Try 1, start the database by restarting the service, and the connection still fails to connect to the server.

Try 2, since the first method does not solve the problem, then the second method. Consider listening Listener.ora

The steps are as follows:

In Oracle Server Oracle installation directory (my under C:\oracle\product\10.2.0\db_1\NETWORK\ADMIN, everyone's not the same, according to their own situation to find, Personal advice to software such as Oracle is best installed to the C disk)
Directory to find the Listener.ora
# Listener.ora Network Configuration File:c:\oracle\product\10.2.0\db_1\network\admin\listener.ora
# Generated by Oracle configuration tools.
Sid_list_listener =
(Sid_list =
(Sid_desc =
(Sid_name = Plsextproc)
(Oracle_home = C:\oracle\product\10.2.0\db_1)
(program = Extproc)
)
(Sid_desc =
(Global_dbname = ORCL)
(Oracle_home = C:\oracle\product\10.2.0\db_1)
(Sid_name = ORCL)
)
)

LISTENER =
(Description_list =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC1))
(ADDRESS = (PROTOCOL = TCP) (HOST = 127.0.0.1) (PORT = 1521))
)
)

The bold part is the instance name I added, ORCL for listening.
It should be noted that host should fill in according to its own situation.

About Oracle "ORA-12514 TNS Listener does not currently recognize request service in connection descriptor" error