Oracle 11g ORA-12514: TNS: The Listener currently cannot identify the Service requested in the connection Descriptor

Solution Process:

1. Find the listener. ora listening file. Location: D: \ app \ Administrator \ product \ 11.2.0 \ dbhome_1 \ Network \ admin \ listener. ora

2. In the lisener. ora file, find

(Sid_desc =
(Sid_name = clrextproc)
(ORACLE_HOME = D: \ app \ Administrator \ product \ 11.2.0 \ dbhome_1)
(Program = EXTPROC)
(Envs = "extproc_dlls = only: D: \ app \ Administrator \ product \ 11.2.0 \ dbhome_1 \ bin \ lrlr11.dll ")
)

Copy the following content and modify it as appropriate. (The red part is your Sid. global_dbname indicates the global database name, which can be different from Sid)

(Sid_desc =
(Global_dbname = 000011)
(ORACLE_HOME = D: \ app \ Administrator \ product \ 11.2.0 \ dbhome_1)
(Sid_name = Limit 11)
)

3. Save the listener. ora file, close and restart the listener.

LSNRCTL stop // disable

LSNRCTL start // start

4. At this time, a new error occurs when a normal user connects to the dual node.

ORA-27101: Shared Memory realm does not exist5. start to open the Directory: D: \ app \ Administrator \ admin \ Users 11 \ pfile, you will find a file: init. ora.1052011103553, which is the Startup File backed up when oracle was last started successfully.
6. sqlplus/nolog, create spfile from pfile = 'd: \ app \ Administrator \ admin \ prop 11 \ pfile \ init. ora.1052011103553 'startup // start the database. 7. everything is back to normal.