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pythongraphqlstrawberry-graphql

GraphQL Query to return non-iterable


I'm using strawberry-graphql in python, and have a query that returns a list of User

@strawberry.type
class User:
    email: str
    name: str

def get_user():
    items = get_from_database()
    return items

@strawberry.type
class Query:
    all_user: List[User] = strawberry.field(resolver=get_user)

schema = strawberry.Schema(Query)

It works fine, but I want some additional attributes like total_item:

def get_user():
    items = get_from_database()
    return {
        'items': items
        'total_item': len(items)
    }

In above code, Strawberry converts the dict to a string, so It didn't work. I tried to create schemas:

@strawberry.type
class User:
    email: str
    name: str

@strawberry.type
class GetUserResult:
    items: List[User]
    item_count: int

def get_user():
    items = get_from_database()
    return GetUserResult(
        items = items
        item_count = len(items)
    )

But it says a query must return an iterable (Expected Iterable, but did not find one for field 'Query.allUser'.).

Is there any way around?


Solution

  • Here's the fixed example:

    from typing import List
    import strawberry
    
    @strawberry.type
    class User:
        email: str
        name: str
    
    def get_user():
        items = [User(email="email", name="Pat")]
        return GetUserResult(
            items=items,
            item_count=len(items)
        )
    
    @strawberry.type
    class User:
        email: str
        name: str
    
    @strawberry.type
    class GetUserResult:
        items: List[User]
        item_count: int
    
    @strawberry.type
    class Query:
        all_user: GetUserResult = strawberry.field(resolver=get_user)
    
    schema = strawberry.Schema(Query)
    

    you can test here too.

    The issue was that in the second snippet you defined:

    def get_user():
        items = get_from_database()
        return GetUserResult(
            items = items
            item_count = len(items)
        )
    

    but the query was still expecting a List of users

    @strawberry.type
    class Query:
        all_user: List[User] = strawberry.field(resolver=get_user)