Remove Object from Active Record Array

Question

In Rails, I have the following Active Record Collection:

@products = Product.all

I need to loop through this collection and remove some objects from it without removing them from the database. Therefore, using

@products.each do |product|
    if CONDITION
        product.delete
    end
end

Won't work, as this will also delete the product from the database. Is there a way to remove specific products from this collection without also deleting them from the database?

Feel free to disregard this, but this is against anything such ORMs are for. ActiveRecotrd is supposed to represent the objects in the database. I recommend you rethink your entire approach - do you really have a good reason for such a hack? — Mörre
– Mörre, Commented Dec 16, 2014 at 18:21
Probably not, but I need to loop through another array as well and compare objects in both arrays to each other. I'm not sure how I would go about fitting that logic into a statement like @products = Product.where(<CONDITIONS>) — Arw50452
– Arw50452, Commented Dec 16, 2014 at 18:37

tagCincy · Accepted Answer · 2014-12-16 18:21:02Z

12

First question, if you don't want the all records, then why even return them from the DB? Why not use a where clause to filter results:

@products = Product.where(<CONDITIONS>)

Second, if you insist on returning all results then filtering, use a .reject block:

@products = Product.all.reject { |p| <CONDITION> }

answered Dec 16, 2014 at 18:21

tagCincy

1,59910 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

11 Comments

Arw50452 Over a year ago

Thanks! I need to nest a loop through another array and compare each object in that array to each object in this array as part of the condition. I wasn't sure how I could accomplish that within @products = Product.where(<CONDITIONS>)

tagCincy Over a year ago

@Arw50452 is the comparison array and array of values (i.e. [1,2,3,4]) or an array of hashes (i.e. [{value: 1}, {value: 2}, {value: 3}])?

Arw50452 Over a year ago

The comparison array is another Active Record Array

tagCincy Over a year ago

Do you care to expand on your use case? I have a feeling that there is a really simple solution to your problem.

Arw50452 Over a year ago

Sure! I have two arrays 1) products 2) requests. The relevant fields in the requests array are: status, requestor_productid, requestee_productid, requestor_userid, and requestee_userid. If all of the following conditions are met for any given product, I want it removed from the products array

|

Tamer Shlash · Accepted Answer · 2014-12-16 18:22:41Z

2

Since Active Record Collections are arrays, you can use reject!:

@products.reject! do |product|
  // your_code
end

If your_code evaluates to true, then product is removed from the collection.

answered Dec 16, 2014 at 18:22

Tamer Shlash

9,5636 gold badges47 silver badges88 bronze badges

2 Comments

ChaosFreak Over a year ago

I get undefined method 'reject' when trying reject on my Active Record Collection. Also tried reject! with same result.

Tamer Shlash Over a year ago

@ChaosFreak can you show us the complete error message?

Collectives™ on Stack Overflow

Remove Object from Active Record Array

2 Answers 2

11 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

11 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related