You might try Upsert:
require 'upsert' # add this to your Gemfile
require 'csv'
u = Upsert.new Moulding.connection, Moulding.table_name
CSV.foreach(file, headers: true) do |row|
selector = { name: row['name'] } # this treats "name" as the primary key and prevents the creation of duplicates by name
setter = row.to_hash
u.row selector, setter
end
If this is what you want, you might also consider getting rid of the auto-increment primary key from the table and setting the primary key to name. Alternatively, if there is some combination of attributes that form a primary key, use that as the selector. No index is necessary, it will just make it faster.