How to correctly query multiple tables?

Question

MySQL

Good evening.
The site is an online store.
My task is to select from the table where product ids and category ids are stored, only those product ids that have category 175. Also, pull out all the data on them (headers, meta tags, and much more that is stored in other tables).
To do this, I concocted such a request. But the trouble is that after such a request, the server is reloaded and all sites on it "give 504". Asked similar request on Denver. The same situation - does not return anything, but all sites that are on Denver stop opening.
PS There are about 20 thousand items of goods on the site.
What could be the problem?
SELECT a.products_id, a.categories_id, b.products_name, b.products_id, b.products_description, b.products_short_description, b.products_keywords, b.products_meta_title, b.products_meta_description, b.products_meta_keywords, c.products_image, c.products_price, c .products_price2, c.products_ordered, d.options_values_price, e.products_attributes_filename, e.products_attributes_password, e.products_attributes_maxdays
FROM products_to_categories a
INNER JOIN products_description b
INNER JOIN products c
INNER JOIN products_attributes d
INNER JOIN products_attributes_products_id e
ON b.products_download
e a.categories_id = 175

Answer 1

Try to add an exclusion of products, for example those with the "Do not show" status.
Use limit .

Answer 2

Are you sure you need the full Cartesian product of all tables? First, add a join condition to each JOIN.