sql命令：

DELETE FROM wp_postmeta WHERE post_id IN (SELECT id FROM wp_posts WHERE post_type = 'revision');
DELETE FROM wp_term_relationships WHERE object_id IN (SELECT id FROM wp_posts WHERE post_type='revision');
DELETE FROM wp_posts WHERE post_type='revision';
DELETE FROM wp_postmeta WHERE meta_key = '_edit_lock';
DELETE FROM wp_postmeta WHERE meta_key = '_edit_last'; DELETE FROM wp_postmeta WHERE meta_key = '_wp_old_slug';
DELETE FROM wp_postmeta WHERE meta_key = '_revision-control';
DELETE FROM wp_postmeta WHERE meta_value = '{{unknown}}';