https://devanswers.co/problem-php-7-2-phpmyadmin-warning-in-librariessql-count/
This error is caused by a line of code in /usr/share/phpmyadmin/libraries/sql.lib.php.
If you don’t want to wait for the repositories to update with the latest version, you can manually upgrade to the latest version of phpMyAdmin yourself.
Alternatively, you can make a small change to sql.lib.php to fix the error.
Firstly, backup sql.lib.php before editing.
sudo cp /usr/share/phpmyadmin/libraries/sql.lib.php /usr/share/phpmyadmin/libraries/sql.lib.php.bakEdit sql.lib.php in nano.
sudo nano /usr/share/phpmyadmin/libraries/sql.lib.phpPress CTRL + W and search for (count($analyzed_sql_results['select_expr'] == 1)
Replace it with ((count($analyzed_sql_results['select_expr']) == 1)
Save file and exit. (Press CTRL + X, press Y and then press ENTER)
Note that this is just a temporary fix and other compatibility issues may crop up until you update phpMyAdmin to the latest version.
If you are also getting an error Warning in ./libraries/plugin_interface.lib.php#551 under import and export tabs, see comments below.