MySQL, a little help with conditions

Question

I have a products table with a stock field and a timestamp field that indicates the last time the product has been updated.

I need to write a query that pulls all the products that have stock>=0 and, for those that stock=0, to check if the difference between the timestamp and the current time is less than 30 days . If stock=0 and datediff(now(), timestamp)>30 then to exclude the products from the recordset.

So far I've written a query (see below) but it's incorrect as it will exclude even the products with stock>0 when they havent been updated in a the past 30 days.

select * from products where stock>=0 and datediff(now(), timestamp)>=30;

Answer 1

SELECT * FROM products 
WHERE 
        stock>0 
OR (
        stock=0
        AND datediff(now(), timestamp)<=30
);

Answer 2

EDIT:

As per your comment, here is the answer very cryptic question

SELECT * FROM products WHERE stock > 0 
OR (stock = 0 and DATEDIFF(NOW(), timestamp) <= 30);

Answer 3

Is it what you want?

SELECT * FROM products WHERE stock > 0 OR stock = 0 AND DATEDIFF(NOW(), timestamp) <= 30;

If stock field is unsigned, the condition 'stock = 0' can be removed.