key: with number type -> type mismatch

[Matan-Perry]

Hi!

I am trying to define a table with an integer as the key.

  class Model
    include Dynamoid::Document

    table name: "table_name", key: :my_key, capacity_mode: :on_demand

    field :my_field, :integer
  end

In my schema i define my_key to be the partition key. when my_key is a string everything work's great, but when i change the schema to :

            attribute_definitions: [
              {
                attribute_name: "my_key",
                attribute_type: "N",  ## (Was S)
              },

I am getting :

     Aws::DynamoDB::Errors::ValidationException:
       One or more parameter values were invalid: Type mismatch for key

I couldn't find any example with a number type key. is this supported?

Thanks

[andrykonchin]

Hi.

First of all - integer/numeric partition keys are supported.

Next. Integer field should be declared with :integer or :number type (not :boolean):

field :my_field, :integer

DynamoDB supports boolean type natively and AFAIK it isn't related or converted implicitly to integer.

Dynamoid supports also storing boolean values (boolean Ruby values - TrueClass/FalseClass) as a DynamoDB string attribute (f and t characters). It's a legacy functionality but it still exists and by default boolean fields are stored as a string attribute (https://github.com/Dynamoid/dynamoid#note-on-boolean-type). That's why in your example the boolean field is stored as a string and it conflicts with the declared partition key type (Number).

[Matan-Perry]

Thanks for the reply. i've used this field as an example, its not the actual field - i edited it.
My question is, how do i tell Dynamoid that my_key is an integer? i keep getting a type mismatch error when passing an integer. when i modify and schema to have a type "S", it works, but only if i use that key as a string.

[andrykonchin]

Could you plz provide a minimal example to reproduce the issue?

In the edited code snippet above I noticed that attribute names (used in table and field calls) are different - my_key and my_field.

Answering your question about declaration of the integer partition key. It should be declared as a field of :integer type. Exactly like you do in your example.

[Matan-Perry]

Could you plz provide a minimal example to reproduce the issue?

In the edited code snippet above I noticed that attribute names (used in table and field calls) are different - my_key and my_field.

Answering your question about declaration of the integer partition key. It should be declared as a field of :integer type. Exactly like you do in your example.

Hey! When i define my_key as a key in the schema, do i need to also define it as a field? in the README example the key is not defined as a field. i added my_field as an example to make the snippet more clear, but i can reproduce is without any fields - just defining a table with a key, the same way as the read me, and trying to make that key an number (type "N") in the schema.

[andrykonchin]

Hey! When i define my_key as a key in the schema, do i need to also define it as a field? in the README example the key is not defined as a field.

Yes, to have a non-String partition key a new field (for this attribute) should be declared explicitly with a needed type.

Example:

    class User
      include Dynamoid::Document

      table key: :numeric_key

      field :numeric_key, :integer
    end

[Matan-Perry]

Thanks !
Looks like that fixes it. does it worth adding an example in the README? or maybe, support for type (:string or :number) in the table definition?

[andrykonchin]

Specifying a hash key type in the table definition is in my TODO list, heh. But it's definitely makes sense to add an example in Readme.