update flask sqlalchemy examples

examples/flask_sqlalchemy/app.py

@@ -12,14 +12,19 @@ default_query = '''
   allEmployees {
     edges {
       node {
-        id
+        id,
-        name
+        name,
         department {
+          id,
+          name
+        },
+        role {
+          id,
           name
         }
       }
     }
-  }
+  },
 }'''.strip()
 
 GraphQL(app, schema=schema, default_query=default_query)

examples/flask_sqlalchemy/database.py

@@ -14,7 +14,7 @@ def init_db():
     # import all modules here that might define models so that
     # they will be registered properly on the metadata.  Otherwise
     # you will have to import them first before calling init_db()
-    from models import Department, Employee
+    from models import Department, Employee, Role
     Base.metadata.drop_all(bind=engine)
     Base.metadata.create_all(bind=engine)
 
@@ -24,10 +24,15 @@ def init_db():
     hr = Department(name='Human Resources')
     db_session.add(hr)
 
-    peter = Employee(name='Peter', department=engineering)
+    manager = Role(name='manager')
+    db_session.add(manager)
+    engineer = Role(name='engineer')
+    db_session.add(engineer)
+
+    peter = Employee(name='Peter', department=engineering, role=engineer)
     db_session.add(peter)
-    roy = Employee(name='Roy', department=engineering)
+    roy = Employee(name='Roy', department=engineering, role=engineer)
     db_session.add(roy)
-    tracy = Employee(name='Tracy', department=hr)
+    tracy = Employee(name='Tracy', department=hr, role=manager)
     db_session.add(tracy)
     db_session.commit()

examples/flask_sqlalchemy/models.py

@@ -10,6 +10,12 @@ class Department(Base):
     name = Column(String)
 
 
+class Role(Base):
+    __tablename__ = 'roles'
+    role_id = Column(Integer, primary_key=True)
+    name = Column(String)
+
+
 class Employee(Base):
     __tablename__ = 'employee'
     id = Column(Integer, primary_key=True)
@@ -19,9 +25,15 @@ class Employee(Base):
     # Employee record was created
     hired_on = Column(DateTime, default=func.now())
     department_id = Column(Integer, ForeignKey('department.id'))
+    role_id = Column(Integer, ForeignKey('roles.role_id'))
     # Use cascade='delete,all' to propagate the deletion of a Department onto its Employees
     department = relationship(
         Department,
         backref=backref('employees',
                         uselist=True,
                         cascade='delete,all'))
+    role = relationship(
+        Role,
+        backref=backref('roles',
+                        uselist=True,
+                        cascade='delete,all'))

examples/flask_sqlalchemy/schema.py

@@ -4,6 +4,7 @@ from graphene.contrib.sqlalchemy import (SQLAlchemyConnectionField,
                                          SQLAlchemyNode)
 from models import Department as DepartmentModel
 from models import Employee as EmployeeModel
+from models import Role as RoleModel
 
 schema = graphene.Schema()
 
@@ -22,8 +23,18 @@ class Employee(SQLAlchemyNode):
         model = EmployeeModel
 
 
+@schema.register
+class Role(SQLAlchemyNode):
+
+    class Meta:
+        model = RoleModel
+        identifier = 'role_id'
+
+
 class Query(graphene.ObjectType):
-    node = relay.NodeField()
+    node = relay.NodeField(Employee)
     all_employees = SQLAlchemyConnectionField(Employee)
+    all_roles = SQLAlchemyConnectionField(Role)
+    role = relay.NodeField(Role)
 
 schema.query = Query