Days ago, shifted WordPress to a new domain name / URL. Right after shifted to new domain name, it shows database error. Took me sometime to surf and google around to find out solutions. In my case, these two ways solved all the problem and the site is now up for good.
i) Went into cPpanel -> public root -> wp-config.php, and change old database name to new one, due to Exabytes technician changed the old name in server side. So, i have to manually change it in WordPress wp-config.php file.
Note: to check your new database name, check it at “MySQLDatabases” in cPanel, under Databases section. if you want to know password for database, you can refer to wp.config.php again, it was stated inside.
ii) took me sometimes to figure on this one, too much of similar articles but none really helps. My case: did all backups but forgot to replace new URL in WordPress -> Setting -> Permalinks. Luckily, found a simple way to do it, stated here: Relocate Method, as below:
1. Edit the wp-config.php file.
2. After the “define” statements (just before the comment line that says “That’s all, stop editing!”), insert a new line, and type: define(‘RELOCATE’,true);
3. Save your wp-config.php file.
4. Open a web browser and manually point it to wp-login.php on the new server. For example, if your new site is at http://www.yourdomainname.com, then type http://www.yourdomainname.com/wp-login.php into your browser’s address bar.
5. Login as per normal.
6. Look in your web browser’s address bar to verify that you have, indeed, logged in to the correct server. If this is the case, then in the Admin back-end, navigate to Settings > General and verify that both the address settings are correct. Remember to Save Changes.
7. Once this has been fixed, edit wp-config.php and either completely remove the line that you added (delete the whole line), comment it out (with //) or change the true value to false if you think it’s likely you will be relocating again.
Note: When the RELOCATE flag is set to true, the Site URL will be automatically updated to whatever path you are using to access the login screen. This will get the admin section up and running on the new URL, but it will not correct any other part of the setup. Those you will still need to alter manually.