sql - Deleting records using delete/where exists problem -

my problem want delete records 2 tables, deleting records result of following query:

select avg(pr.rating) rating_average products p  inner join product_ratings pr  on pr.product_id = p.product_id   group p.product_id  having avg(pr.rating) < 3 

the above query shows average ratings of product less 3, want delete products , associated ratings of results above query.

i looked @ delete product_ratings, products exists (//above query), didn't work, i've been trying various delete statements no avail.

i have read following, , still cannot find solution: sql: delete statement & sql: exists condition.

the tables products , product_ratings, following structure:

products -------- product_id [pk] | link | ...  product_ratings --------------- rating_id [pk] | rating | product_id 

appreciate help, links reference material better understand how it's done.

edit: apologies not stating rdbms i'm using, it's mysql

edit2: bit confused now, @martin's example doesn't use temp table other answers, assume because of vague question not stating rdbms using?

you have added mysql tag. in case might job you.

delete products,        product_ratings   products,        product_ratings  product_ratings.product_id = products.product_id        , product_ratings.product_id in   (select product_id           (select p.product_id                   products p                        left join product_ratings pr                          on pr.product_id = p.product_id                 group  p.product_id                 having coalesce(avg(pr.rating), 0) < 3) t)  

mysql does support multiple table delete syntax. derived table around issue doesn't allow mutating (update or delete target) tables referenced in sub query (it materializes result temporary table).