ORA-12545: The connection failed because the target host or object does not exist!

Error reason is configuration error hostname

Solve:

1. Search for your own installed Oracle path, find these two files Tnsnames.ora and Listener.ora, modify these two files, modify host= own host name

My path is as follows: G:\oracle\product\10.2.0\db_1\NETWORK\ADMIN

After the modification is complete, restart the listener and the server.

You can also look at the client configuration:

See if the host name is correct in Oracle Net Manager.

Sometimes this is the cause of the impact.

Reboot the listener and restart the computer if it does not, 100% so!

ORA-12545: The connection failed because the target host or object does not exist!