Drush 9 is finally here with some much-awaited changes. Drush 9 commands are now classes and .inc files are obsolete. Drush commands will now be based on the Annotated Command format. This will change the fundamental structure of custom Drush commands.
When you remove a module manually or re import a database, some times you have a message like "The following module is missing from the file system...". this is due to deleted modules.
Drush allow to download and install drupal core, drupal modules and drupal themes.
Note : It is recommended to use composer to manage drupal 8, modules and themes.
To create a custom drush command, you must create a custom module like this (Here, mymodule).
drush_invoke (For the current site)drush_invoke($command, $arguments = array());
drush cr
drush sql-dump > /pathto/mysql-dump-drupal8.sql
drush sql-drop
drush sql-cli
mysql> source /pathto/mysql-dump-drupal8.sql
Features is a drupal contrib module enables the capture and management of features in Drupal, by providing a UI and API for taking different site building components from modules with exportables and bundling them together in a single feature module.
1. Go to Administration > Configuration > Development > Performance
(/admin/config/development/performance)
2. Click on "Clear all caches"
drush cache-rebuild
OR
drush cr
Example (basic)
drush migrate-upgrade --legacy-db-url=mysql://user:password@server/db --legacy-root=http://mydrupal6or7site.com
# Download latest stable release using the code below or browse to github.com/drush-ops/drush/releases.
# Example: drush 8.4.5
php -r readfile('https://github.com/drush-ops/drush/releases/download/8.4.5/drush.phar'); > drush
#OR