QueryDoc.rst

Query

Queries require specifying the GraphQL schema and a Query type. For example Lets have a model Document with a name field:

# models.py
from django.db import models

class Document(models.Model):
    name = models.CharField(max_length=50, null=False, blank=False)

    def __str__(self):
        return self.name

For the Query, we define a GraphQL schema and a Query type in type_defs where they Query contains the name of the Query getDocument with the input fields (id and name) followed by the format of the return object [Document], which returns a list of Documents. The return object can also be customized by adding an additional schema type for tasks such as handling returning error issues.

from ariadne import gql, QueryType
from ariadne import make_executable_schema
from core.schema import type_defs, query
from django.db.models import Q


type_defs = gql("""
   type Document {
        id:ID
        name: String!
   }

    type Query {
        getDocument(name:String, id:ID): [Document]
    }

""")

query = QueryType()

@query.field("getDocument")
def resolve_getDocument(*_, name=None, id=None,):
    if name:
        filter = Q(name__icontains=name)
        return Document.objects.filter(filter)
    if id:
        filter = Q(id__exact=id)
        return Document.objects.filter(filter)
    return Document.objects.all()

schema = make_executable_schema(type_defs, query)

The resolver is a function beginning with resolve_ followed by the name of the query and the input fields.

In this example, a filter is applied when name or id is present where the results will return the Document with the exact id entered or a list of Documents containing the entry in name. If no values are entered, the query will get all objects. The filters are based on the Django Field lookups.

To modify the ordering of the results, the Query type and the queries in the resolver can be modified where you can enter "name" for ascending order by name and "-name" for descending.

type_defs = gql("""
   type Document {
        id:ID
        name: String!
   }

    type Query {
        getDocument(name:String, id:ID, order:String): [Document]
    }

""")

query = QueryType()

@query.field("getDocument")
def resolve_getDocument(*_, name=None, id=None, order=None):
    if name:
        filter = Q(name__icontains=name)
        return Document.objects.filter(filter).order_by(order)
    if id:
        filter = Q(id__exact=id)
        return Document.objects.filter(filter).order_by(order)
    return Document.objects.all().order_by(order)