Question

Let’s say we have two tables here , posts and comments, the relations is one to many, there has a field call comment_date in the comments table.

Now I am struggle to get the expected results as follow:

All the posts have no comments after a certain date, can I done this by a SQL statement?

Answer 1

SELECT *
FROM posts p
WHERE NOT EXISTS(
    SELECT 1
    FROM comments c
    WHERE c.comment_date >= 'deadline'
    AND p.post_id = c.post_id
)