GraphQL query returning duplicate results

Question

I have a GraphQL schema that returns orders and the products that are part of that order. I have added a filter to return only orders that contains products searched for by the user. This filter is done on a icontains.

However I have found that if a user searches for angel for example, and an order contains two or more products that contain the string angel it returns the order that many times duplicating the records returned to the frontend.

Query:

{
  dateFilterList
  Purchases(first: 15, after: "", username_Icontains: "", PurchaseOrdersProductsOrderId_ProductName: "angel") {
    pageCursors {
      previous {
        cursor
      }
      first {
        cursor
        page
      }
      around {
        cursor
        isCurrent
        page
      }
      last {
        cursor
        page
      }
      next {
        cursor
      }
    }
    edges {
      node {
        id
        cmOrderId
        username
        date
        articles
        merchandiseValue
        shippingValue
        trusteeValue
        totalValue
        products {
          edges {
            node {
              id
              productId
              productName
              productNumber
            }
          }
        }
      }
    }
  }
}

Json Response:

{
  "data": {
  ...
  "purchases": {
    ...
      "edges": [
        {
          "node": {
            "id": "",
            "cmOrderId": 12345,
            "username": "UserA",
            "date": "2022-06-29T16:38:51",
            "articles": 40,
            "merchandiseValue": "",
            "shippingValue": "",
            "trusteeValue": "",
            "totalValue": "",
            "products": {
              "edges": [
                {
                  "node": {
                    "id": "",
                    "productId": "",
                    "productName": "Angel of Grace",
                    "productNumber": "1"
                  }
                },
                {
                  "node": {
                    "id": "",
                    "productId": "",
                    "productName": "Angel of Sanctions",
                    "productNumber": "1"
                  }
                },
                ...
              ]
            }
          },
          "node": {
            "id": "",
            "cmOrderId": 12345,
            "username": "UserA",
            "date": "2022-06-29T16:38:51",
            "articles": 40,
            "merchandiseValue": "",
            "shippingValue": "",
            "trusteeValue": "",
            "totalValue": "",
            "products": {
              "edges": [
                {
                  "node": {
                    "id": "",
                    "productId": "",
                    "productName": "Angel of Grace",
                    "productNumber": "1"
                  }
                },
                {
                  "node": {
                    "id": "",
                    "productId": "",
                    "productName": "Angel of Sanctions",
                    "productNumber": "1"
                  }
                },
                ...
              ]
            }
          },
          ...

Schema:

# region Integration Purchase Orders
class PurchaseOrderFilter(FilterSet):
    class Meta:
        model = purchase_orders
        fields = {'date': ['gt', 'lt', 'isnull'], 'username': ['icontains'],}

    purchase_orders_products_order_id__product_name = CharFilter(lookup_expr="icontains")


class PurchaseOrderProductFilter(FilterSet):
    class Meta:
        model = purchase_orders_products
        fields = {"product_name": ["icontains"]}


class PurchasesProducts(DjangoObjectType):
    id = graphene.ID(source='pk', required=True)

    class Meta:
        model = purchase_orders_products
        interfaces = (graphene.relay.Node,)
        filterset_class = PurchaseOrderProductFilter


class Purchases(DjangoObjectType):
    id = graphene.ID(source='pk', required=True)
    products = DjangoFilterConnectionField(PurchasesProducts)

    class Meta:
        model = purchase_orders
        interfaces = (graphene.relay.Node,)
        filterset_class = PurchaseOrderFilter
        connection_class = ArtsyConnection

    @staticmethod
    def resolve_products(self, info, **kwargs):
        return purchase_orders_products.objects.filter(order_id=self.id).order_by('product_name').all()


class PurchasesQuery(ObjectType):
    date_filter_list = graphene.List(graphene.List(graphene.String))
    purchases = ArtsyConnectionField(Purchases)

    @staticmethod
    def resolve_date_filter_list(self, info, **kwargs):
        years = purchase_orders.objects.filter(user_id=info.context.user.id).annotate(year=ExtractYear('date'), month=ExtractMonth('date'), ).order_by().values_list('year', 'month').order_by('-year', '-month').distinct()
        return years

    @staticmethod
    def resolve_purchases(self, info, **kwargs):
        return purchase_orders.objects.filter(user_id=info.context.user.id).all().order_by("-date")


PurchasesSchema = graphene.Schema(query=PurchasesQuery)
# endregion

Asked By: Ross

||

Source

Answer 1

Problem

Your query is likely returning duplicate results. It’s sometimes not enough to just call .distinct().

Solution

You must specify DISTINCT ON <field> as it seems your id field is returning an empty string. Consider a adding .distinct('cmOrderId') to your query.

I also notice that most of your purchase_order_product queries do not include distinct—consider adding the .distinct('cmOrderId') to all of these queries.

Notes

Furthermore, I notice that you call all() on your filter() queries—it has no effect on the resulting object.

References

https://docs.djangoproject.com/en/4.0/ref/models/querysets/#filter

https://docs.djangoproject.com/en/4.0/ref/models/querysets/#django.db.models.query.QuerySet.distinct

Answered By: pygeek

GraphQL query returning duplicate results

Question:

Answers:

Problem

Solution

Notes

References