The six most common errors encountered when using Oracle databases

1. ORA-12541: TNS: No listener

Cause: the listener is not started or damaged. For the former, run the net start OracleOraHome81TNSListener command (the name may be different). For the latter, you can add a listener to "Listener Configuration" in the "Net8 Configuration Assistant" tool wizard. (no information is required. You may need to delete all listeners before adding them !)

2. ORA-12500: TNS: The Listener cannot start the dedicated server process

Or

ORA-12560: TNS: protocol adapter error.

Cause: ORACLE Database Service is not started. Run the net start ORACLESERVICEORADB command (ORADB is the database name. If the problem persists, proceed to the following section.

3. If the database service fails to be started, the registry key value may be corrupted. The best practice is to perform the following two steps:

1) ORADIM-DELETE-SID oradb deletes database service items

2) ORADIM-NEW-SID oradb adds database service items

Note: if an error occurs during this process, restart the computer!

4, ORA-12154: TNS: can resolve the service name

Cause: the network service name of ORACLE is not correctly configured. Use "Local Network Service name Configuration" in the "Net8 Configuration Assistant" tool Wizard to configure TNS. If the problem persists, proceed to the following section.

5. ORA-1034: TNS: ORACLE unavailable

Cause: the ORACLE Database Service is correctly started, but the database is not opened!

Run the following command:

1) svrmgrl start the Service Manager

2) connect internal logs in as internal

3) startup open the database

6. ORA-12560: TNS: protocol adapter error (stubborn)

Cause: unknown.

Solution: Be sure to activate the Windows Task Manager, kill oracle.exeand oradim.exe processes, write your own ora_startup.bat, and execute it!

PS:

1. My ora_startup.bat:

Net start OracleOraHome81TNSListener

Net start ORACLESERVICEORADB

Svrmgrl is generally not used, but sometimes it is indispensable. For detailed steps, see step 1.

2. My ora_shutdown.bat:

Net stop OracleOraHome81TNSListener

Net stop ORACLESERVICEORADB

3. for ORACLE service names, see service names starting with ORACLE in "services" in "Administrative Tools"