Question

I’m a bit new to JOIN and I’m finding it difficult to understand how I can query one table with ORDER BY and LIMIT and using only ORDER BY on my JOINED ‘right’ table I think it is? So Basically if I was to query the two tables individually I would use these queries:

SELECT * FROM posts ORDER BY dateSubmitted DESC LIMIT ?,5 

‘?’ standing for my bind_param() because I’m creating a pagination. Now for my ‘right’ Second table:

SELECT * FROM postcomments WHERE postcomments.postID = posts.ID ORDER BY dateSubmitted DESC

As far as my understanding goes to ‘link’ the two tables together I want to be using LEFT JOIN so that I will receive all my data from the ‘left’ table (being posts).

SELECT * FROM posts LEFT JOIN postcomments ON postcomments.postID = posts.ID

Now I can do this but I’m unsure where I would but my ORDER BY and LIMIT for both tables?
I’ve seen several different ways and I think this is what’s getting me confused like I’ve seen this:

SELECT p.* FROM posts p ORDER BY posts.dateSubmitted DESC LIMIT ?,5 
LEFT JOIN (SELECT * FROM postcomments 
WHERE postscomments.postID = p.ID ORDER BY postcomments.dateSubmitted);

But I’m really unsure how to structure my query :S Any help appreciated 🙂

Answer 1

It will be at the end like this:

Select * from
(SELECT * FROM posts  ORDER BY dateSubmitted DESC LIMIT ?,5) as tempPost
LEFT JOIN postcomments on (postscomments.postID = tempPost.ID)