It seems JIRA database corrupted, how to fix that issue.
How do you know its corrupted? There could be different reasons for connections failure. Check if there are firewall changes in your organisation that has blocked the connection.
First of all there could be several reasons.
1. You need to now where your database is running( which server, is it running ? )
2. Make sure You don't have network issues btw database server and Jira server( if you are running Jira on your own server
3.dbconfig.xml could be faulty, make sure that the user name and password is correct for the user which jira uses to connect to database
4. other things you could do try to ping the IP address of your database server and see whether or not you get response.
5. Check jira logs /database server logs :)
6. See also KB article https://confluence.atlassian.com/jirakb/startup-check-jira-database-connections-872262124.html