You can easily disable all WordPress plugins directly from your database. This is useful when you have some problems with your WordPress installation such as not being able to log in to the admin area and/or having blank pages.
To disable all plugins, log in to phpMyAdmin and select your WordPress database from the menu on the left.
Browse the table wp_options and find the option active_plugins. Click the pencil icon to edit the table. Its content will vary, depending on what plugins you have enabled. For example, if you have the Akismet and Hello Dolly plugins enabled, the code there will be:
a:2:{i:0;s:19:"akismet/akismet.php";i:1;s:9:"hello.php";}
To disable all plugins, simply delete the code and click the Go button to save the change.
The other option is to use the following query to disable all of your WordPress plugins:
UPDATE wp_options SET option_value = '' WHERE option_name = 'active_plugins';
Please note that disabling the plugins will not remove them from your WordPress application. They will simply be deactivated. You can easily activate them from your WordPress admin area at any time.