After a power failure, the oracle database cannot be started

  
   There are many solutions on the Internet about "the oracle database cannot be started after a power failure", but the whole process is not very complete. Some only have an ending, some only have a beginning and an ending, and some only have a middle paragraph.

    My database is also because the oracle database cannot be started after the power outage, so I specially collected the solution. I have restored the database according to the scenario.


Attached below is the solution.