官网中关于ORA-12560的解释：
ORA-12560: TNS:protocol adapter error
Cause: A generic protocol adapter error occurred.
Action: Check addresses used for proper protocol specification. Before reporting this error, look at the error stack and check for lower level transport errors. For further details, turn on tracing and reexecute the operation. Turn off tracing when the operation is complete.
首先检查windows服务中Oracle实例相关服务是否运行：
WIN（图标键）+R👇
检查Oracle配置文件
进入Oracle安装主目录\product\12.2.0\dbhome_1\network\admin
打开tnsnames.ora配置文件：
打开listener.ora配置文件：
检查对应数据库的HOST配置是否正确？此处HOST=<PC主机名>
如何查看主机名？👇
重启监听：
打开命令行输入：lsnrctl restart
重启服务：
总结
