Warning & Fatal error if paste code to wp-config.php

Hi,

If I paste this code to wp-config.php:

require(‘./db-settings.php’);

My site show me these error codes:

Warning: require(./db-settings.php) [function.require]: failed to open stream: No such file or directory in /home/user/public_html/wp-config.php on line 94

Warning: require(./db-settings.php) [function.require]: failed to open stream: No such file or directory in /home/user/public_html/wp-config.php on line 94

Fatal error: require() [function.require]: Failed opening required './db-settings.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/user/public_html/wp-config.php on line 94

But if I paste this code:

require('/home/user/public_html/db-settings.php');

My site work, but the plugin say:

Error: You must configure your database settings by adding require('./db-settings.php'); to your /home/user/public_html/wp-config.php for the migration process to work

What is the solution?

Thanks!

https://ww.wp.xz.cn/plugins/shardb/