Question

just looking a way to avoid repeated post on my site, here is a basic scheme of my tables:

posts:
+----+-------------------- +
| ID | post_date           |
+----+---------------------+
| 1  | 2011-11-15 08:42:50 |
+----+---------------------+

meta:
+--------------------+------------+
| post_id | meta_key | meta_value |
+---------+----------+------------+
|    1    |    ip    |192.168.1.10| 
+---------+----------+------------+

I’m not sure how to build the query but the basics are:

• Block by IP, so, I need to provide it.
• Users can post every 300 secs.
• return empty when user is allowed, otherwise return ID and post date from their latest post.

Answer 1

The following query will return 1 when the user is allowed to post. The second will return the id and post date for the user’s ip last post.

select 1 from post,meta
    where meta.meta_value=<ip>
    and post.id = meta.post_id
    and post.post_date = max(select post_date from post,meta where meta.meta_value=<ip> and post.id = meta.post_id)
    and post.post_date = (now()+300));

select post.id, post.post_date from post,meta
    where meta.meta_value=<ip>
    and post.id = meta.post_id
    and post.post_date = max(select post_date from post,meta where meta.meta_value=<ip> and post.id = meta.post_id);

You can even merge them using the ifnull function but you will not be able to use 2 columns for the second statement is that case.

select ifnull(statement 1, statement 2);