Oracle11g: ORA-12545: connection failure issues because the target host or object does not exist

Oracle11g: ORA-12545: connection failure problem because the target host or object does not exist 1. find the oracle installation directory and find the two files tnsnames. ora and listener. ora. Their path is as follows: drive letter: app \ Administrator \ product \ 11.1.0 \ db_2 \ NETWORK \ ADMIN
They edit these two files in the same directory and change the Host = field to your computer name. Www.2cto.com 2. if you log in at this time, you will be prompted that you do not have a listener, that is, the listening service is not enabled. The method to access the service from the computer service is as follows: control Panel> Management Tools> Service (the icon of the two gears), find the Oracle-Listener service, and start it.