Feature Request: Query Predicate Operation: attributeExists

[MarlonJD]

Description

Hello, on amplify-flutter there is no attributeExists on where parameters while ModelQueries.list.

I needed this when eq(null) was not enough, If there is no key in dynamodb it gives false result, so we need this attributeExists in these cases.

ModelQueries.list(Employee.classType,
            where: Employee.COGNITOID.attributeExists(false));

I'm planning to add this, what do you about it?

Detailed Example Use Case, why we need this?

Post(title: "Lorem ipsum", blog: null, ...)

we want to list posts with no blogs assigned, if belongsTo model was null, in dynamoDB there wouldn't be any attribute. So if we try to list this:

final req = ModelQueries.list(
  Post.classType,
  where: Post.BLOG.eq(null),
  limit: _limit,
);

it won't give us right results. it should've customized document and variables for this.

This feature allow us to do this.

Categories

• Analytics
• API (REST)
• API (GraphQL)
• Auth
• Authenticator
• DataStore
• Notifications (Push)
• Storage

Steps to Reproduce

No response

Screenshots

No response

Platforms

• iOS
• Android
• Web
• macOS
• Windows
• Linux

Flutter Version

3.3.10

Amplify Flutter Version

0.6.10

Deployment Method

Amplify CLI

Schema

No response

[MarlonJD]

I just add #4134 for this issue

[Equartey]

@MarlonJD Awesome, thanks for opening a pull request!

We need to review this internally before we can take your changes. Will provide updates as I have them.

[MarlonJD]

@Equartey I can clone and try to pass tests, I was did some online GitHub edit quickly then tests not working for now

[Equartey]

@MarlonJD No need, tests are not the issue. We need to review the implementation to ensure it doesn't collide with DataStore category.

[MarlonJD]

@Equartey yes, that's true, I didn't test datastore side, okay than I'll wait your response about it, thanks.

[Equartey]

@MarlonJD apologies for the delay. Your feature work has been merged 🎉

We will let you know when its released and available. Thanks again for your contribution, it's highly appreciated!

[MarlonJD]

@Equartey Thanks for your corrections on the PR, you did great work for datastore and tests, I'm happy that it's merged. 🎉

[Jordan-Nelson]

This was added in Amplify Flutter v2 which was released a couple weeks ago. There were some breaking changes in this version. Please see the upgrade guide for more info.

@MarlonJD Thanks for opening the issue and your contributions!