Combining 2 MySQL queries - php

Question

I have 2 queries:
SELECT sql_cache distinct p.products_image,
p.products_subimage1,
pd.products_name,
p.products_quantity,
p.products_model,
p.products_ordered,
p.products_id,
p.products_price,
p.products_date_added,
p.products_weight,
p.products_length,
p.products_width,
p.products_height,
p.products_tax_class_id,
p.products_status,
IF(s.status, s.specials_new_products_price, NULL) AS specials_new_products_price,
IF(s.status, s.specials_new_products_price, p.products_price) AS final_price
FROM products p
LEFT JOIN specials s
ON p.products_id = s.products_id
LEFT JOIN products_to_categories p2c
ON p.products_id=p2c.products_id
LEFT JOIN products_description pd
ON p.products_id=pd.products_id
INNER JOIN filter_association_products fap
ON p.products_id =fap.products_id
LEFT JOIN products_attributes pa
ON p.products_id = pa.products_id
WHERE p.products_status = '1'
AND date_sub(curdate(),INTERVAL 3000 day) <= p.products_date_added
AND fap.filter_id = 126
ORDER BY p.products_date_added DESC,
pd.products_name
Which gives me a result of 52 rows (products).
And an identical query with only difference:
AND fap.filter_id = 130
Which gives me a result of 4 rows.
One of the common things between these rows/products is that 3 out of the 4 with filter_id 130 also have filter_id 126 and I want to modify the query to give me results of only products with both (or even more, depends on the filter_ids applied) of the indicated filter_id.
I have tried
...
AND FIND_IN_SET(fap.filter_id,'126', '130')
ORDER BY p.products_date_added DESC, pd.products_name
But I get a result of 53 rows/products, meaning it's showing all the products that have either filter, while the result I am looking for in this case is of only the 3 rows that have both filter_id.
What is the best way to rewrite the query to get the correct results?

Answer 1

Use GROUP BY to get the product information that you want. You can join in additional information as well, but this is the basic query:
SELECT p.*
FROM products p JOIN
specials s
ON p.products_id = s.products_id JOIN
products_to_categories p2c
ON p.products_id = p2c.products_id JOIN
products_description pd
ON p.products_id = pd.products_id JOIN
filter_association_products fap
ON p.products_id = fap.products_id JOIN
products_attributes pa
ON p.products_id = pa.products_id
WHERE p.products_status = '1' AND
date_sub(curdate(),INTERVAL 3000 day) <= p.products_date_added AND
fap.filter_id IN (126, 130)
GROUP BY p.products_id
HAVING COUNT(DISTINCT fap.filter_id) = 2; -- make sure both match
I don't see any reason for the LEFT JOINs (at least for most of the tables, because everything up to filter_association_products is being turned into an inner join by the WHERE clause), so I changed them to inner joins.

Answer 2

Make two LEFT JOIN's on filter_association_products and filter in WHERE, like this:
SELECT sql_cache distinct p.products_image,
p.products_subimage1,
pd.products_name,
p.products_quantity,
p.products_model,
p.products_ordered,
p.products_id,
p.products_price,
p.products_date_added,
p.products_weight,
p.products_length,
p.products_width,
p.products_height,
p.products_tax_class_id,
p.products_status,
IF(s.status, s.specials_new_products_price, NULL) AS specials_new_products_price,
IF(s.status, s.specials_new_products_price, p.products_price) AS final_price
FROM products p
LEFT JOIN specials s
ON p.products_id = s.products_id
LEFT JOIN products_to_categories p2c
ON p.products_id=p2c.products_id
LEFT JOIN products_description pd
ON p.products_id=pd.products_id
LEFT JOIN filter_association_products fap1
ON p.products_id =fap1.products_id
LEFT JOIN filter_association_products fap2
ON p.products_id =fap2.products_id
LEFT JOIN products_attributes pa
ON p.products_id = pa.products_id
WHERE p.products_status = '1'
AND date_sub(curdate(),INTERVAL 3000 day) <= p.products_date_added
AND fap1.filter_id = 126
AND fap2.filter_id = 130
ORDER BY p.products_date_added DESC,
pd.products_name
Another approach (sub select) :
SELECT sql_cache distinct p.products_image,
p.products_subimage1,
pd.products_name,
p.products_quantity,
p.products_model,
p.products_ordered,
p.products_id,
p.products_price,
p.products_date_added,
p.products_weight,
p.products_length,
p.products_width,
p.products_height,
p.products_tax_class_id,
p.products_status,
IF(s.status, s.specials_new_products_price, NULL) AS specials_new_products_price,
IF(s.status, s.specials_new_products_price, p.products_price) AS final_price
FROM products p
LEFT JOIN specials s
ON p.products_id = s.products_id
LEFT JOIN products_to_categories p2c
ON p.products_id=p2c.products_id
LEFT JOIN products_description pd
ON p.products_id=pd.products_id
LEFT JOIN products_attributes pa
ON p.products_id = pa.products_id
WHERE p.products_status = '1'
AND date_sub(curdate(),INTERVAL 3000 day) <= p.products_date_added
AND 126 in (select fap1.filter_id from filter_association_products fap1
where p.products_id = fap1.products_id)
AND 130 in (select fap2.filter_id from filter_association_products fap2
where p.products_id = fap2.products_id)
ORDER BY p.products_date_added DESC,
pd.products_name

Answer 3

While both answers by Mikey and Gordon Linoff are good, I preferred Gordon's approach due to its extensibility. However, his answer has some syntax errors and the switch to JOINs didn't produce any results, so I had to revise them back to LEFT JOINs, as suggested by Mikey. (Thank you both).
This is the final query that works:
SELECT sql_cache distinct p.products_image,
p.products_subimage1,
pd.products_name,
p.products_quantity,
p.products_model,
p.products_ordered,
p.products_id,
p.products_price,
p.products_date_added,
p.products_weight,
p.products_length,
p.products_width,
p.products_height,
p.products_tax_class_id,
p.products_status,
IF(s.status, s.specials_new_products_price, NULL) AS specials_new_products_price,
IF(s.status, s.specials_new_products_price, p.products_price) AS final_price
FROM products p
LEFT JOIN specials s
ON p.products_id = s.products_id
LEFT JOIN products_to_categories p2c
ON p.products_id=p2c.products_id
LEFT JOIN products_description pd
ON p.products_id=pd.products_id
INNER JOIN filter_association_products fap
ON p.products_id =fap.products_id
LEFT JOIN products_attributes pa
ON p.products_id = pa.products_id
WHERE p.products_status = '1'
AND date_sub(curdate(),INTERVAL 3000 day) <= p.products_date_added
AND fap.filter_id IN (126, 130)
GROUP BY p.products_id
HAVING COUNT(DISTINCT fap.filter_id) = 2;