graphql，当有"add"和"update"突变时如何设计输入类型？

Question

这是我的要求：

"add" 突变，BookInput 输入类型的每个字段（或称为标量）都应该有额外的类型修饰符“！”验证非空值。这意味着当我添加一本书时，参数必须有 title 和 author 字段，例如 {title: "angular", author: "novaline"}
"update"突变，我想更新书的一部分字段，不想更新整本书（MongoDB文档，而且，我不不希望前端向 graphql 服务器传递一整本大书变异参数以节省带宽）。这意味着 book 参数可以是 {title: "angular"} 或 {title: "angular", author: "novaline"}.

这是我的类型定义：

const typeDefs = `
  input BookInput {
    title: String!
    author: String!
  }

  type Book {
    id: ID!
    title: String!
    author: String!
  }

  type Query {
    books: [Book!]!
  }

  type Mutation{
    add(book: BookInput!): Book
    update(id: String!, book: BookInput!): Book
  }
`;

目前，"add" 突变工作正常。但是如果我传递 {title: "angular"} 参数

，"update" 突变无法通过非空检查

这是一个未通过非空检查的突变，BookInput 输入类型缺少 "author" 字段。

mutation {
  update(id: "1", book: {title: "angular"}) {
    id
    title
    author
  }
}

所以，graphql 会给我一个错误：

{
  "errors": [
    {
      "message": "Field BookInput.author of required type String! was not provided.",
      "locations": [
        {
          "line": 2,
          "column": 24
        }
      ]
    }
  ]
}

如何设计BookInput输入类型？不想定义 addBookInput 和 updateBookInput。重复了。

Answer 1

一个非常常见的模式是为每个突变使用单独的输入类型。您可能还想为每个操作创建一个突变查询。也许是这样的：

const typeDefs = `
  input AddBookInput {
    title: String!
    author: String!
  }

  input UpdateBookInput {
    # NOTE: all fields are optional for the update input 
    title: String
    author: String
  }

  type Book {
    id: ID!
    title: String!
    author: String!
  }

  type Query {
    books: [Book!]!
  }

  type Mutation{
    addBook(input: AddBookInput!): Book
    updateBook(id: String!, input: UpdateBookInput!): Book
  }
`;

有些人还喜欢将更新 ID 作为更新输入的一部分：

const typeDefs = `
  input AddBookInput {
    title: String!
    author: String!
  }

  input UpdateBookInput {
    # NOTE: all fields, except the 'id' (the selector), are optional for the update input 
    id: String!
    title: String
    author: String
  }

  type Book {
    id: ID!
    title: String!
    author: String!
  }

  type Query {
    books: [Book!]!
  }

  type Mutation{
    addBook(input: AddBookInput!): Book
    updateBook(input: UpdateBookInput!): Book
  }
`;

最后，您可能希望对 return 类型使用 'payload' 类型 - 以增加灵活性（为您提供更多回旋余地以在以后更改 return 类型而不会破坏您的API):

const typeDefs = `
  input AddBookInput {
    title: String!
    author: String!
  }

  input UpdateBookInput {
    # NOTE: all fields, except the 'id' (the selector), are optional for the update input 
    id: String!
    title: String
    author: String
  }

  type Book {
    id: ID!
    title: String!
    author: String!
  }

  type AddBookPayload {
    book: Book!
  }

  type UpdateBookPayload {
    book: Book!
  }

  type Query {
    books: [Book!]!
  }

  type Mutation{
    addBook(input: AddBookInput!): AddBookPayload!
    updateBook(input: UpdateBookInput!): UpdateBookPayload!
  }
`;

希望对您有所帮助！

Answer 2

这是我的解决方案，我写了一个辅助函数来生成 "create" input 类型和 "update" input 类型。

const { parse } = require('graphql');

/**
 * schema definition helper function - dynamic generate graphql input type
 *
 * @author https://github.com/mrdulin
 * @param {string} baseSchema
 * @param {object} options
 * @returns {string}
 */
function generateInputType(baseSchema, options) {
  const inputTypeNames = Object.keys(options);
  const schema = inputTypeNames
    .map(inputTypeName => {
      const { validator } = options[inputTypeName];
      const validatorSchema = Object.keys(validator)
        .map(field => `${field}: ${validator[field]}\n`)
        .join(' ');

      return `
      input ${inputTypeName} {
        ${baseSchema}
        ${validatorSchema}
      }
    `;
    })
    .join(' ')
    .replace(/^\s*$(?:\r\n?|\n)/gm, '');

  parse(schema);
  return schema;
}

schema.js:

${generateInputType(
  `
  campaignTemplateNme: String
`,
  {
    CreateCampaignTemplateInput: {
      validator: {
        channel: 'ChannelUnionInput!',
        campaignTemplateSharedLocationIds: '[ID]!',
        campaignTemplateEditableFields: '[String]!',
        organizationId: 'ID!',
      },
    },
    UpdateCampaignTemplateInput: {
      validator: {
        channel: 'ChannelUnionInput',
        campaignTemplateSharedLocationIds: '[ID]',
        campaignTemplateEditableFields: '[String]',
        organizationId: 'ID',
      },
    },
  },
)}

graphql，当有"add"和"update"突变时如何设计输入类型？

graphql, how to design input type when there are "add" and "update" mutation?

graphql

graphql-js

apollo-server