Delete duplicate records based on multiple columns

Question

In our system we run hourly imports from an external database. Due to an error in the import scripts, there are now some duplicate records.

A duplicate is deemed where a

Answer 1

You can try the following approach:

Product.where.not(
  id: Product.group(:legacy_id, :company).pluck('min(products.id)')
).delete_all

Or pure sql:

delete from products
where id not in ( 
   select min(p.id) from products p group by p.legacy_id, p.company
)