Mysql：对多条记录应用条件

Question

I have a MySQL table to store product variants option values (eg: colour, size, weight, the height of product variants). It contains the following data.

I have a filter option on the frontend, where users can select filter options such as colour, size, weight, height etc and I need to show product variants based on the filter values.

In the above example: option_id = 110 means size. option_id = 109 means color. Suppose a user-selected size = 31 (XL) and colour = 27 (Red),

I have to find a product_variant_id where option_id = '110' AND option_value_id = 31 AND option_id = '109' AND option_value_id = 27. (result should be records with ids 266 and 267)

There is only one such product_variant_id that is 140.

I tried

SELECT * FROM product_variant_option_values WHERE (option_id = '110' AND option_value_id = 31) OR (option_id = '109' AND option_value_id = 27)

but it's not returning what I want, the above query returns

Answer 1

OK, after seeing the result you are getting right now. If I understand correctly, you want product_variant_id that has exactly the two conditions you mentioned. So one option for a query could be:

SELECT product_variant_id
FROM product_variant_option_values 
WHERE (option_id = '110' AND option_value_id = 31) OR (option_id = '109' AND option_value_id = 27)
GROUP BY product_variant_id
HAVING count(*) = 2

Which means, that you count the number of rows returned per each product_variant_id and only return the one that has 2 rows. Which means got the two conditions.

Answer 2

I think what you can do is to add a COUNT() operation to see if both of the filter condition are met. Something like below:

SELECT   product_variant_id,COUNT(*) cnt 
FROM     product_variant_option_values 
WHERE    (option_id = '110' AND option_value_id = 31) 
  OR     (option_id = '109' AND option_value_id = 27)
GROUP BY product_variant_id
HAVING   cnt >= 2;

Grouped by product_variant_id whereby the result of COUNT() is 2 or more; of if the filter condition is always going to be 2 then just HAVING cnt=2 should suffice. This query can similarly be written this way:

SELECT   product_variant_id,COUNT(*) cnt 
FROM     product_variant_option_values 
WHERE    option_id in ('110','109') 
  AND    option_value_id IN (27,31)
GROUP BY product_variant_id
HAVING   cnt >= 2;

Fiddle example : https://www.db-fiddle.com/f/9kKmyHsSAMNk4BBPDWLHFh/3