CODEWITHSUNDEEP
amazon-dynamodb
JohnDoe
JohnDoe

Reputation: 11

Dynamodb GetItem with contains


I'm facing an issue with dynamodb, I'm new to this and it seems so hard to understand... while it seems "easy" with SQL
I hope you will be able to help me understand what I'm missing :)
I have some information, like this: 

Role
- identifier (hash)
- label 

User
- identifier (hash)
- label
- roleIdentifierList (each role is a different user... I don't like this, but that's the only way to get a range here I guess)

Item
- identifier (hash)
- roleIdentifier (global secondary index)
- label

How, with an "user identifier" and an "item identifier" could I be sure that this user has the correct role?
I'm afraid my tables aren't well formed but documentation seems a little bit light.

Thanks!

I'm currently doing a scan on User to get all roles of user with identifier
Then, I've try (but without success because we can't use "contains" with getItem) to retrieve the item with the correct id and at the same time check if there is the correct role.
Is this correct to do a getItem and then in another logic rule (not related with dynamodb), check if the role is present?

Upvotes: 0

Views: 98

Answers (1)

Leeroy Hannigan
Leeroy Hannigan

Reputation: 19883

Without going into your datamodel and access patterns, the simple answer is for you to use Query API, which will allow you to provide a FilterExpression where you can use contains.

aws dynamodb query \
--table-name my-table-name \
--key-condition-expression "#pk = :pk" \
--filter-expression "contains(#y, :y)" \
--expression-attribute-values '{ ":y": { "S": "some identiier" }, ":pk": { "S": "abc" }}' \
--expression-attribute-names '{"#y":"some attribute name", "#pk":"identifier"}'

https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html

Upvotes: 1

Related Questions