I have run into some database problems over the years, but had to do something different today when I saw that this site had a problematic table (wp_posts). When I looked at the issue first, I got the message “MySQL error code 145 = Table was marked as crashed and should be repaired”.
To repair a table, I have run (at a mysql prompt in the command line): REPAIR TABLE wp_posts; but today that did not work. After doing some research, I finally was able to fix the table by using: myisamchk -r wp_posts (see documentation. This was a lifesaver!