Apollo Client:未定义变量.收到状态码 400 [英] Apollo Client: Variable is not defined. Received status code 400

问题描述

我正在尝试使用 Apollo 客户端在 GraphQL 查询中使用动态变量.我遵循了文档，但是 Apollo 一直给我错误，说我的变量没有定义，最终以状态代码 400 响应.

I'm trying to use dynamic variable in a GraphQL query using Apollo Client. I have followed the documentation, but Apollo keeps giving me errors, saying that my variables are not defined, and ultimately responding with status code 400.

以下是 Apollo 的文档内容:

Here is what the documentation for Apollo said:

mutate: (options?: MutationOptions) => Promise从您的 UI 触发突变的函数.您可以选择将变量、optimisticResponse、refetchQueries 和 update 作为选项传递，这将覆盖传递给 Mutation 组件的任何道具.该函数返回一个满足您的变异结果的承诺.

mutate: (options?: MutationOptions) => Promise A function to trigger a mutation from your UI. You can optionally pass variables, optimisticResponse, refetchQueries, and update in as options, which will override any props passed to the Mutation component. The function returns a promise that fulfills with your mutation result.

这是我尝试编写的代码:

And here is the code I tried to write:

const fetch = require('node-fetch');
const ApolloClient = require('apollo-boost').default;
const gql = require('graphql-tag');

const client = new ApolloClient({
    uri: "http://api.domain.com/graphql",
    fetch
});

run();

async function run() {
    try {
        const resp = await client.mutate({
            mutation: gql`mutation {
                trackPr(id: $id, pr: $pr, title: $title, body: $body, state: $state, merged: $merged) {
                    id
                }
            }`,
            variables: {
                id: 1,
                pr: 1,
                title: "test title",
                body: "test body",
                state: "test state",
                merged: false
            },
        });


        console.log(resp.data);
    } catch(ex) {
        console.log(ex);
    }
}

然后我会收到每个变量的错误消息，指出它尚未定义:

I'll then get a error message for each variable saying it has not been defined:

[GraphQL 错误]:消息:变量$id"未定义，位置:[object Object],[object Object]，路径:undefined

[GraphQL error]: Message: Variable "$id" is not defined., Location: [object Object],[object Object], Path: undefined

在每条错误消息之后，我都会收到一条状态代码为 400 的最终消息:

After each of these error messages, I then get a final message with status code 400:

[网络错误]:ServerError:响应不成功:收到状态码400

[Network error]: ServerError: Response not successful: Received status code 400

在没有变量和直接在突变中设置的所有值的情况下，突变本身运行良好，但我不知道为什么它认为变量未定义.

The mutation itself runs fine without the variables and all the values set directly in the mutation, but I don't know why it thinks the variables are not defined.

推荐答案

在操作中使用的任何变量都必须声明为操作定义的一部分，如下所示:

Any variables used inside an operation must be declared as part of the operation definition, like this:

mutation SomeOptionalMutationName ($id: ID!) {
  trackPr(id: $id) {
    id
  }
}

这允许 GraphQL 根据提供的类型验证您的变量，并验证是否正在使用变量代替正确的输入.

This allows GraphQL to validate your variables against the provided type, and also validate that the variables are being used in place of the right inputs.

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