GraphQL和Graphene

Question

我有一个具有一对多关系的数据库模式。对于例如一个部门有很多客户。是否有可能创建客户和部门并将其关联起来？或者正确的方法是创建客户而不是部门，然后相互关联？

在第二种方法中，我需要进行三次而不是一次。 有人能为我提供处理这种情况的GraphQL吗？

Answer 1

您可以定义突变输入以支持嵌套类型。这样您就可以在单个变异中发送Department和Customer。

在返回有效内容中，您可以在查询中指定返回新创建的Department及其关联的Customer。

class Customer(graphene.ObjectType):
    customer_id = graphene.Int(required=True)
    name = graphene.String(required=True)


class Department(graphene.ObjectType):
    department_id = graphene.Int(required=True)
    name = graphene.String(required=True)
    customers = graphene.List(Customer)


class CustomerInput(graphene.InputObjectType):
    name = graphene.String(required=True)


class DepartmentMutation(graphene.relay.ClientIDMutation):

    class Input:
        name = graphene.String(required=True)
        customer = graphene.Field(CustomerInput)

    department = graphene.Field(Department)

    @classmethod
    def mutate_and_get_payload(cls, input, context, info):
        new_department_name = input.get('name')
        new_customer = input.get('customer')
        logger.debug(new_department_name)
        logger.debug(new_customer)
        # validate and persist...
        # we return dummy objects for brevity
        customer = Customer(
            customer_id=1,
            name=new_customer.get('name')
        )
        department = Department(
            department_id=1,
            name=new_department_name,
            customers=[customer]
        )
        return cls(department=department)

您将允许您在一次旅行中变异和查询关联实体。

如果您使用Connections来定义关系，事情会变得有点复杂，但基本原则是相同的。