After creating a database, you also need to create a listener by yourself. There are many ways to create a listener, as follows: 1. graphical interface: 1.1 netca is a simple graphical interface. It is recommended that you use it for beginners. The specific usage will not be detailed and the configuration will be successful as prompted (the basic step is the next step... OK) 1.2 netmgr is a more troublesome graphical method than netca. It involves listening services, database services, and other configurations, including the port number, ip address (or host name), and Oracle Home Directory, SID (this must be consistent with the SID of the data to be connected), Global Database Name. Note: enter netmgr directly under win to call the GUI in this way. 2. Change the Script Mode directly. [oracle @ elvisadmin] $ pwd/u01/oracle/product/11.2.0/dbhome_1/network/admin [oracle @ elvisadmin] $ cat listener. ora # listener. ora Network Configuration File:/u01/oracle/product/11.2.0/dbhome_1/network/admin/listener. ora # Generated byOracle configuration tools. SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (GLOBAL_DBNAME = elvis) (ORACLE_HOME =/u01/oracle/product/11. 2.0/dbhome_1) (SID_NAME = elvis) LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP) (HOST = elvis) (PORT = 1521 )))) after configuring the listening service for ADR_BASE_LISTENER =/u01/oracle, you can run the lsnrctl command directly. Lsnrctl -- listner control abbreviation-> start -- an error message is displayed when the first start is performed, and the listener information is registered in the Registry and displayed in the service, if the error message Win is not displayed during the second startup, you can enable it directly in the service. Refresh the service and a listener will appear, then start observation again -- it is best to change to automatic