Create QueryDoc.rst (#56)

Added docs for query

Docs/QueryDoc.rst

@@ -0,0 +1,96 @@
+Query
+-----
+
+Queries require specifying the GraphQL schema and a Query type. For
+example Lets have a model ``Document`` with a name field:
+
+.. code:: python
+
+   # 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.
+
+.. code:: python
+
+   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.
+
+.. code:: python
+
+   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)