AWS amplify Graph QL 按书名和作者姓名过滤

Posted 2023-03-08

【中文标题】AWS amplify Graph QL 按书名和作者姓名过滤

【英文标题】：AWS amplify Graph QL filter by book title and author name

【发布时间】：2021-04-06 19:16:58

【问题描述】：

AWS amplify DynamoDB Graph QL 按书名和作者姓名过滤

我想按书名和作者姓名搜索书籍，但我的架构允许我按书名和作者 ID 而不是作者姓名搜索书籍我如何实现这一点。

以下是我的图形 ql 架构

type Author 
  @model(subscriptions: null)
  @auth(
    rules: [
      # allow admins to create, update and delete books
       allow: groups, groups: ["owner"] 
      # allow all authenticated users to view books
       allow: private, operations: [read] 
    ]
  )
  @key(name: "authorByCreatedAt", fields: ["isDeleted", "createdAt"], queryField: "authorByCreatedAt")
  
  id: ID!
  name: String!
  description: String!
  status : Boolean!
  createdAt: String!
  image: String!
  isDeleted: Int!
  books: [Book] @connection(keyName: "byAuthor", fields: ["id"])


type Book 
  @model(subscriptions: null)
  @auth(
    rules: [
      # allow admins to create, update and delete books
       allow: groups, groups: ["owner"] 
      # allow all authenticated users to view books
       allow: private, operations: [read] 
    ]
  )
  @key(name: "bookByCreatedAt", fields: ["isDeleted", "createdAt"], queryField: "bookByCreatedAt")
  @key(name: "byAuthor", fields: ["authorId"])
  
    id: ID!
    title: String!
    description: String!
    image: String!
    age: Int!
    region: String!
    isbn: String
    narrator: String
    status : Boolean!
    createdAt: String!
    isDeleted: Int!
    book: String!
    bookType: BookType!
    authorId: ID!
    authors: Author @connection(fields: ["authorId"])
  

enum BookType 
  AUDIO
  EPUB

【参考方案1】：

如果您来自关系数据库领域，这似乎应该是微不足道的。在 DynamoDB 的世界中，它更加复杂。您不能创建链接到@connection 的@key（据我所知）。这个问题的一些解决方案：

1：在书中添加作者姓名

作者的姓名通常不会更改，因此您可以执行以下操作。在 DynamoDB/NoSQL 世界中，复制数据并不令人讨厌。这也会为您提供更快的查询。

type Book 
  @model(subscriptions: null)
  @key(name: "BooksByAuthorName", fields: ["authorName"], queryField: "getBooksByAuthorName")
  
    id: ID!
    title: String!
    description: String!
    image: String!
    age: Int!
    region: String!
    isbn: String
    narrator: String
    status : Boolean!
    createdAt: String!
    isDeleted: Int!
    book: String!
    bookType: BookType!
    authorId: ID!
    authorName: String
    authors: Author @connection(fields: ["authorId"])
  

2：自定义解析器

自定义解析器，如 @function（Lambda 函数），或更复杂的 custom resolver 模板可用于多个搜索和自定义逻辑，但我建议先使用选项 1。

3：探索@searchable指令

See this for more info