It can be sometime handy to query recently modified (last month or last few days) posts in wordpress mysql tables. Here are some handy queries:
Posts modified in last month
Approach 1 using MINUS
SELECT * from wp_posts where post_modified > NOW() - INTERVAL 1 MONTH ORDER BY post_modified DESC;
Approach 2 using DATE_ADD
SELECT * from wp_posts where post_modified > DATE_ADD(NOW(), INTERVAL - 1 MONTH) ORDER BY post_modified DESC;
Approach 3 using DATE_SUB
SELECT * from wp_posts where post_modified > DATE_SUB(NOW(), INTERVAL 1 MONTH) ORDER BY post_modified DESC;
Posts modified in last week
SELECT * from wp_posts where post_modified > NOW() - INTERVAL 1 WEEK ORDER BY post_modified DESC;
Posts modified in last 1 day
SELECT * from wp_posts where post_modified > NOW() - INTERVAL 1 DAY ORDER BY post_modified DESC;
Posts modified in last 1 hour
SELECT * from wp_posts where post_modified > NOW() - INTERVAL 1 HOUR ORDER BY post_modified DESC;