MySQL使用几个WHERE子句选择AVG

Question

I have a search engine for an online shop, i want to give the user the chance to filter the products by rating, until now my query looks like this:

SELECT products.*,prices.price,AVG(ratings_products.rating)
FROM products,prices,ratings_products
WHERE products.title REGEXP 'lg' AND products.active = 'yes'
AND prices.price >= '10' AND prices.price <= '298650'
AND products.cod_product = prices.id_product
AND ratings_products.ratings >= '40' AND ratings_products.ratings <= 59
AND ratings_products.id_product = products.cod_product
AND products.id_category = '59' LIMIT 0,1

The idea is to filter by price, specific filters and rating, all works except the ratings. I have the table ratings_products with the following structure:

id | id_product | id_user | title | comment | date | rating
1  |      18    |    65   |awesome| some    |12344 | 85
2  |      18    |    84   |cool   | great   |12345 | 20

Now i need to AVG to return the average between 85 and 20, but the query is returning NULL, if i delete the ratings_products.rating <= 59 it gives me the result but is not calculating the average.

Appreciate any help

Thanks

Answer 1

AND ratings_products.ratings >= '40' AND ratings_products.ratings <= 59

This means you want the values between 40 and 59. You display 20 and 85 in your example, neither is in the range you query for so that result is NULL

Removing the AND ratings_products.ratings <= 59 part leaves a query for ratings higher than 40, that is 85, on its own, nothing to average.

Am I missing something or are you querying for the wrong values?