Ecto Query returns ">="

I’m writing a query to get shopping carts with duplicate products in them. I have a Cart that has_many Items. I’m trying to query carts with duplicated items in the cart, but I only want to look in specific carts that have been abandoned so I’ve written a query like this:

 from(itm in Item,
      join: cart in Cart,
      on: == itm.cart_id,
      where: cart.status in ["abandoned"],
      join: itm2 in Item,
      on: != and itm.cart_id == itm2.cart_id and c.product_id == itm2.product_id,

Perhaps this is overly verbose, but I’m looking for items, where the associated cart is ‘abandoned’, then I want to see if those items are duplicated (same product in the same cart) and return the item ids.

The above query returns >='. However; if I change the last line to select: %{id:}I'll get a list of maps with the correct item IDs. This confirms to me that the query works but for some reason, if I just want the IDs, not as a map something goes wrong. I've tried writing the query a few other ways and sometimes I get a=>` returned as well but it’s the same thing, if I wrap it in a map it returns the right IDs.

Are the IDs 62 and 61?

What you see here is a “charlist”, just a different representation of the same thing. '>=' and [62, 61] are identical.


Thanks man. That was driving me crazy! I guess Elixir defaults to charlist when it sees a list where all values are less than ~255?

Printable ASCII characters AFAIR.


If all integers in a list are printable characters then yes, Elixir prints them as a character list.

It’s a constant source of confusion for newcomers and there are threads about it on a regular basis.

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