Snippet for properly handling all phpMyAdmin cases in NGINX. Collected somewhere from Stack Overflow.

nginx-phpmyadmin.conf

# Phpmyadmin Configurations
location /phpmyadmin {

	root /usr/share/;
	index index.php index.html index.htm;
	location ~ ^/phpmyadmin/(.+\.php)$ {

		try_files $uri =404;
		root /usr/share/;
		fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
		fastcgi_index index.php;
		fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
		include fastcgi_params;
	}
	location ~* ^/phpmyadmin/(.+\.(jpg|jpeg|gif|css|png|js|ico|html|xml|txt))$ {
		root /usr/share/;
	}
}

# Dealing with the uppercased letters
location /phpMyAdmin {
	rewrite ^/* /phpmyadmin last;
}