Today, when I moved my site to new server, I got an error with database. At first, I got an error like
“Unknown column ‘t.topic_visibility’ in ‘where clause’  site:www.phpbb.com“. After searching for the solution, I couldn’t find the right ones, then I went to re-upload the database again and again but still didn’t work. Somehow, I got another error “Table ‘….phpbb_ext’ doesn’t exist “. Then I continue go to find a solution….
After many attempts dropping and re-imported the database but still unsuccessful. I tried Google and took me a lot of time getting my website working again. To preserve for my next time error and share with all of you how I did it. I don’t know it is the right way, but at least, it worked and my site up again.
Here is how an error looked like.
SQL ERROR [ mysql4 ]
Table ‘yourdatabasename.phpbb_ext’ doesn’t exist 
An sql error occurred while fetching this page. Please contact an administrator if this problem persists.
Then here is what I did.
I run “install/database_update.php”
Then the screen displayed the result like
I tested my site and there were no error such as above, but I’m still unable to see my site because I hadn’t delete/rename the folder “install”. So, I went to delete the folder “install” in my site directory. Then when I went back my site, everything worked fine. I’m so happy that I solved the problem without searching further more. Hope these tips can help some of you whom are on the same boat with me.
I guess, I got the error because my phpbb hadn’t update for a while. When I moved to the new server, I downloaded the latest version of phpbb package (phpbb 3….). Then imported my existing database to phpMyAdmin. The site ended up run in latest version of phpbb in old mysql. That’s what I guess because I wasn’t sure that’s a cause.