PHP install goes bust during upgrade



You may be able to just uninstall the old config, if you know how to re-install all of the components that you need using
sudo apt-get -y purge php.*
The problem may be that when 5.5 came along, some of the main database libraries which were commonly used were deprecated and so this could mean having to do a lot of changes to the code. It may be a case of having to stick with an older version of PHP or to get the app updated.
If you are experiencing difficulties connecting PHP 5.6 to MySQL 5.7, it might be due to deprecated database libraries and compatibility issues. In such cases, you have a few options:

  1. Uninstall and reinstall: You can try uninstalling the current PHP configuration and then reinstalling it, ensuring that you include the necessary components. Use the command sudo apt-get -y purge php.* to uninstall PHP, and then reinstall it along with the required extensions.
  2. Stick with an older PHP version: If updating the application's codebase to work with newer PHP versions and database libraries is not feasible, you may need to consider sticking with the older version of PHP that is compatible with the existing code.
  3. Update the application: If possible, updating the application's codebase to work with newer PHP versions and compatible database libraries would be the ideal solution. This would involve modifying the code to use the appropriate database functions and libraries supported by PHP 5.6 and MySQL 5.7.