How to skip specific tables with drush sql-dump?

Question

I have a drush config file ~/.drush/drushrc.php:

if (!isset($options['structure-tables']['common'])) {
  $options['structure-tables']['common'] = array(
    'cache', 'cache_*', 'history', 'search_*', 'sessions', 'watchdog'
  );
}

$options['structure-tables']['common'] = array_merge($options['structure-tables']['common'], 
  array('ctools_css_cache', 'ctools_object_cache', 'logz', 'views_object_cache')
);

And I have a bash script file:

/usr/bin/drush sql-dump --root="/home/username/domains/sitename/www" --skip-tables-key="common" --gzip --result-file=/home/username/backup/$year/$month/dbname_$date_now_time.sql

But when I execute it the backup file still have data in cache tables. What am I doing wrong?

And second question is - If I put this into crontab do I need to put configuration file somewhere else?

I use Drush version 8.

Answer 1

Sorry I can't help you much with your first question ...

Your 2nd question asked:

And second question is - If I put this into crontab do I need to put configuration file somewhere else?

The drush documentation site links to drushrc.php example file that says where you may place the rc file:

https://raw.githubusercontent.com/drush-ops/drush/master/examples/example.drushrc.php

Rename this file to drushrc.php and optionally copy it to one of the places listed below in order of precedence:

1. Drupal site folder (e.g. sites/{default|example.com}/drushrc.php).
2. Drupal /drush and sites/all/drush folders, or the /drush folder in the directory above the Drupal root.
3. In any location, as specified by the --config (-c) option.
4. User's .drush folder (i.e. ~/.drush/drushrc.php).
5. System wide configuration folder (e.g. /etc/drush/drushrc.php).
6. Drush installation folder.

For Cron the documentation recommends that Drush be configured to run as the same user that runs your webserver. That being said I recommend you place your rc file in location (5), a system-wide configuration folder. Yes, more localized Drush rc files will then need to override your system-wide configuration file as needed (oh well).

Answer 2

Dump all tables except the cache table and tables starting with cache_.

drush sql-dump --skip-tables-list=cache,cache_* > dumpfile.sql

Database structure only. No data at all.

drush sql-dump --extra=--no-data > dumpfile.sql

Data only. No cache data and no cache structure.

drush sql-dump --skip-tables-list=cache,cache_* --data-only > dumpfile.sql

No cache data but dump in their structures.

drush sql-dump --structure-tables-list=cache,cache_* > dumpfile.sql

sql-dump documentation

Answer 3

For some reason cache_* did not work for me with drush 9+ until I omitted the underscore. However, this may be specific to my (server) bash/terminal. What worked for me:

drush sql-dump --skip-tables-list=cache*

and you can always add the --verbose to see the actual mysql dump and it's --ignore parameter.