I'm currently using 2 queries to obtain some data and would like to know if I can
combine these two queries into one query.
I have a database with 3 tables:
1. A category table
2. A product table
3. A normalized "catproduct" table that is used to determine which product is in which
category. A product may be in multiple categories.
I have a website where when a person navigates to a category it shows all the products. I
would like to create a "related categories" list by finding all the categories the
products in the current category belong to.
Right now I use 2 SQL statements:
1. The first query gets all the products in the current category.
SELECT product_table.prod_id FROM
LEFT JOIN catproduct_table ON (catproduct_table.product_id =
WHERE (catproduct_table.category_id = '1') LIMIT 5
2. The second query gets all the categories that these products belong to:
SELECT category_table.category FROM category_table
LEFT JOIN catproduct_table ON (catproduct_table.category_id =
LEFT JOIN product_table ON (product_table.product_id = catproduct_table.product_id)
WHERE product_table.prod_id IN ('1000,1001,1002,1003,1004')
These two queries are my proof of concept so I'm only limiting the first query to 5
results. In reality I have thousands of products per category so I prefer not to limit
the first query. I don't have many categories so the results of the second query are
Is there anyway to combine these 2 queries into 1?