Add GraphQL schema

schema.py

@@ -0,0 +1,38 @@
+import graphene
+from graphene import relay
+from graphene_sqlalchemy import SQLAlchemyObjectType, SQLAlchemyConnectionField
+from models import (Department as DepartmentModel, Employee as EmployeeModel)
+
+
+class Department(SQLAlchemyObjectType):
+    class Meta:
+        model = DepartmentModel
+        interfaces = (relay.Node,)
+
+
+class DepartmentConnection(relay.Connection):
+    class Meta:
+        node = Department
+
+
+class Employee(SQLAlchemyObjectType):
+    class Meta:
+        model = EmployeeModel
+        interfaces = (relay.Node,)
+
+
+class EmployeeConnection(relay.Connection):
+    class Meta:
+        node = Employee
+
+
+class Query(graphene.ObjectType):
+    node = relay.Node.Field()
+    # Allows sorting over multiple columns, by default over the primary key
+    all_employees = SQLAlchemyConnectionField(EmployeeConnection)
+    # Disable sorting over this field
+    all_departments = SQLAlchemyConnectionField(DepartmentConnection,
+                                                sort=None)
+
+
+schema = graphene.Schema(query=Query)