Oralce TNS: The Listener cannot identify the connection currently.

After installing Oralce, I want to connect to it. The result is that I cannot connect to the client through PL/SQL. The prompt is TNS: The Listener cannot identify the connection currently.
Solution:

1. view the local/$/Oracle/oracle/network/admin/
Vi tnsnames. ora didn't change the port 1523 before it was changed. I changed it to 1521.

SALES =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP) (HOST = localhost. localdomain) (PORT = 1521 ))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = sales)
)
)

LISTENER_SALES =
(ADDRESS = (PROTOCOL = TCP) (HOST = localhost. localdomain) (PORT = 1521 ))


EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC3 ))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)

2. Check listener. ora again.
The default value is as follows: no sales in tnsnames. ora
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME =/mapbar/oracle)
(PROGRAM = extproc)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC3 ))
(ADDRESS = (PROTOCOL = TCP) (HOST = localhost. localdomain) (PORT = 1523 ))
)

To add: The red part is newly added.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME =/$/oracle)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = sales)
(ORACLE_HOME =/$/oracle)
(SID_NAME = sales)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC3 ))
)
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP) (HOST = localhost. localdomain) (PORT = 1521 ))
)
)

3. Execute lsnrctl stop
Lsnrctl start