select data from table which dont have row in another table

Question

I have 2 tables. First "product" (id). Second - "product_has_option_value" (product_id, option_value_id).

How can I get product ids which doesn't have some option_value_id (for example 10)? "product_has_option_value" has many to many relationships.

Ok. I think I found the solution:

select p.id 
from product p 
where p.id not in 
  (select distinct(product_id)
   from product_has_option_value 
   where option_value_id=543)

Answer 1

What you want is called "anti-join" (or "anti-semijoin"). There are 3 main ways to do this kind of query in MySQL (and some more in other DBMS, that have implemented EXCEPT operator):

• NOT IN subquery (no need for DISTINCT here but you may need to add the check AND pov.product_id IS NOT NULL if that column is nullable):

  select p.id 
  from product as p 
  where p.id not in 
    ( select pov.product_id
      from product_has_option_value as pov 
      where pov.option_value_id = 543
        and pov.product_id is not null
    ) ;
  

• LEFT JOIN with IS NULL check:

  select p.id 
  from product as p 
      left join  product_has_option_value as pov 
        on  pov.option_value_id = 543
        and pov.product_id = p.id
  where pov.product_id is null ;
  

• NOT EXISTS correlated subquery:

  select p.id 
  from product as p 
  where not exists 
    ( select 1
      from product_has_option_value as pov 
      where pov.option_value_id = 543
        and pov.product_id = p.id
    ) ;
  

Answer 2

This is what you are looking for:

SELECT * FROM product
LEFT JOIN product_has_option_value ON product.id = product_has_option_value.product_id
WHERE product_has_option_value.product_id IS NULL