GraphQL和Apollo Federation的新功能。
我有一个问题,是否可以用另一个数据集填充一个数据集,例如:
# in Shop Service
type carId {
id: Int
}
type Shop @key(fields: "id") {
id: ID!
name: String
carIds: [CarId]
}
# in Car Service
type Car {
id: ID!
name: String
}
extends type Shop @key(fields: "id") {
id: ID! @external
cars: [Car]
}
汽车解析器
Query{...},
Shop: {
async cars(shop, _, { dataSources }) {
console.log(shop); // Issue here is it returns the references that are an object only holding the `id` key of the shop, I need the `cars` key here, to pass to my CarsAPI
return await dataSources.CarsAPI.getCarsByIds(shop.carsIds);
}
}
在Shop rest api中,响应如下:
[{id: 1, name: "Brians Shop", cars: [1, 2, 3]}, {id: 2, name: "Ada's shop", cars: [4,5,6]}]
在Car rest api中,响应如下:
[{id: 1, name: "Mustang"}, {id: 2, name: "Viper"}, {id: 3, name: "Boaty"}]
所以我要存档的是查询我的GraphQL服务器以获取:
Shop(id: 1) {
id
name
cars {
name
}
}
然后期望:
{
id: 1,
name: "Brian's shop",
cars: [
{name: "Mustang"},
{name: "Viper"},
{name: "Boaty"}
]
}
有可能吗,这就是我选择联盟时的想法:)
答案 0 :(得分:1)
因此,如果在您发表评论后我能正确理解,您想要的是让carIds
分解器中的cars
商店服务进入您的Car服务。
您可以使用@requires
指令,该指令将指示Apollo Server在开始执行cars
解析程序之前需要一个(或几个)字段。那就是:
汽车服务
extend type Shop @key(fields: "id") {
id: ID! @external
carIds: [Int] @external
cars: [Car] @requires(fields: "carIds")
}
现在,在cars
解析器内部,您应该可以在第一个参数上访问shop.carIds
。
请参阅:https://www.apollographql.com/docs/apollo-server/federation/advanced-features/#computed-fields