WordPress plugins can be easily disabled from the database. You just have to open your favorite client and connect to your favorite client and go to your site database. I normally use HeidSQL, phpMyAdmin or Adminer but you can use any other. For this specific task you must know your database connection credentials. If you have an FTP connection you can find that in your wp-config.php file on the wordpress installation root
You will have to go to the wp_options table and search for a specific value in the option_name column. Please note that the table prefix ( wp ) is the standard prefix but can be different from one installation to another.
You have to search for active_plugins , so after selecting the option table, go to your Search tab to do that.
You can also run the next SQL sentence to search for the active_plugins key
SELECT * FROM `wp_options` WHERE `option_name` LIKE 'active_plugins'
To deactivate or disable all plugins on your WordPress installation you must delete the option_value content like you can see below.
IMPORTANT: You may be interested in saving your that value before deleting it just in case you want to restore it at a later time.
There is also a quicker way to do this by running this next SQL sentence. but I prefer the first way since I get to save the value before doing any changes to my database.
UPDATE wp_options SET option_value = '' WHERE option_name LIKE 'active_plugins'
Please let me know if you know other ways to disable all wordpress plugins directly from the database.