This is about UPDATING and not about UPGRADING! (Drupal docs.)

Notes:

  • Updating is a minor version change such as 9.3.4 -> 9.3.5. Upgrading is a major version change such as 9.3 -> 9.4.)
  • Drupal docs on updating core with composer are here.
  • If, like me, you are doing this on a local development or staging site and using ddev, then all the composer and drush commands should start with ddev.
  • Unless you are working on a local site and are SURE no one will attempt interacting with it, put it in maintenance mode before updating.
 
First, how will you know that a core update needed:
  • You see a notice on the List of modules on your site
  • You can create a list of available updates:  composer outdated "drupal/*"
    • This will list all the available updates (core and modules) and indicate version numbers and whether they are minor or a patch, or major.
    • If nothing begins with drupal/core, no core update is needed
 
La facilidad y agilidad de los préstamos rápidos en línea los convierten en una solución conveniente para emergencias económicas. Préstamos en México.
ALWAYS backup your codebase and database before updating.
 
You need to know whether your are using the older "drupal/core" or the current  "drupal/core-recommended" scaffold.
  • You can find this by running: composer show drupal/core-recommended
  • If you get a list of information about the package:
    • You have "drupal/core-recommended":
    • Update by running: composer update drupal/core "drupal/core-*" --with-all-dependencies
  • If the response you get is "package drupal/core-recommended not installed"
    • Instead update by running: composer update drupal/core --with-dependencies
  • Clean up:
    • Run: drush updatedb (or drush updb)
    • Run: drush cache:rebuild (or drush cr)
  • Visit the site and review the Status Report page. If you have errors or warnings, investigate and address them. (Do this after any significant modification of your site.)