Can't perform a UNION ALL MySQL query

[eluser]Ci beginner[/eluser]
[quote author="kgill" date="1248733521"]

Actually I don’t know how to make it with separate queries

You're overthinking this:

Code:

$this->db->select(first query here);
$something = $this->db->get();

// repeat for each of the other queries
$this->db->select(2nd query here);
$something_else = $this->db->get();

// etc.

[/quote]

I can't do it... imagine this situation: we have a blog, with a query that gets the latest 5 posts. Now, we need to count the comments for every post, to write near the title "X comments". And the only way to do it is with UNION ("blog" for posts and "comentarios_blog" for comments), not with two queries, I think. But I'm unable to perform UNION thing because I don't know how to do in CI...

Thanks!