[英]Apollo GraphQL - resolver not being triggered
我是 GraphQL 的新手。 我從 Javascript Apollo 庫開始,但無法觸發解析器。 我很難判斷何時應該調用解析器,以及應該放置什么鍵。
這是我的架構和解析器:
// The GraphQL schema in string form
const typeDefs = `
type Query { user(id: ID!): User, posts: Post }
type User { id: ID!, created: Int, username: String, bio: String, status: String, avatar: String, posts: [Post] }
type Post { id: ID!, created: Int, user_id: Int, text: String, object_set_id: Int, edited: Int, views: Int, upvotes: Int, downvotes: Int, Parent: Int }
`;
// The resolvers
const resolvers = {
Query: {
user: (parent, args, context, info) => {
return users.find(user => user.id === Number(args.id));
},
// posts: () => posts,
},
Post: {
id: (parent, args, context, info) => {
console.log(posts.filter(post => post.user_id === Number(parent.id)))
return posts.filter(post => post.user_id === Number(parent.id))
}
}
};
我想通過用戶 ID 指定用戶,然后過濾以獲取用戶發布的所有帖子(最終使用時間過濾器)。
我嘗試了幾件事,但是用戶下的“帖子”總是顯示為“空”。 我錯過了什么? 謝謝。
您的第一個查詢工作正常。 您還應該添加一些data
(否則您會收到錯誤"message": "users is not defined",
)。
執行查詢:
query{
user(id: 1){
id
username
}
}
基本代碼示例:
const { ApolloServer, gql } = require("apollo-server");
const users = [
{
id: 1,
username: "Kate Chopin"
},
{
id: 2,
username: "Paul Auster"
}
];
// The GraphQL schema in string form
const typeDefs = gql`
type Query {
userById(id: ID!): User
}
type User {
id: ID!
username: String
}
`;
// The resolvers
const resolvers = {
Query: {
userById: (parent, args, context, info) => {
return users.find((user) => user.id === Number(args.id));
}
}
};
const server = new ApolloServer({
typeDefs,
resolvers
});
server.listen().then(({ url }) => {
console.log(`🚀 Server ready at ${url}`);
});
postById
): 關於posts
- 您的查詢是posts
並且沒有解析器匹配 + 看起來您對他們做了一點“沙拉”。
最好遵循這個例子(同樣的想法只有書籍/作者而不是帖子/用戶): https : //www.apollographql.com/docs/apollo-server/getting-started/
接下來,閱讀這個解析器鏈: https : //www.apollographql.com/docs/apollo-server/data/resolvers/#resolver-chains
再次hello world
例子
const posts = [
{
id: 1,
name: "Article One"
},
{
id: 2,
name: "Article Two"
}
];
const users = [
{
id: 1,
username: "Kate Chopin",
posts: posts
},
{
id: 2,
username: "Paul Auster"
}
];
// The GraphQL schema in string form
const typeDefs = gql`
type Query {
userById(id: ID!): User
}
type User {
id: ID!
username: String
posts: [Post]
}
type Post {
id: ID!
name: String
}
`;
// The resolvers
const resolvers = {
Query: {
userById: (parent, args, context, info) => {
return users.find((user) => user.id === Number(args.id));
}
}
};
const server = new ApolloServer({
typeDefs,
resolvers
});
server.listen().then(({ url }) => {
console.log(`🚀 Server ready at ${url}`);
});
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