Question

我不确定自己在做什么错。我无法使用GraphQL来查询这似乎是一个非常简单的API？

https://data.brreg.no/enhetsregisteret/enhet.json

我尝试了不同的解决方案。但是我遇到了相同的错误/问题。

import { ApolloServer, gql, IResolverObject } from "apollo-server";
import fetch from "node-fetch";

const typeDefs = gql`
    type Company {
        organisasjonsnummer: Int
        navn: String
    }

    type Query {
        companies: [Company!]!
    }
`;

const resolvers: IResolverObject = {
    Query: {
        companies: async () => {
            const response = await fetch(
                "https://data.brreg.no/enhetsregisteret/enhet.json"
            );
            const data = await response.json();
            return data.results;
        }
    }
};

const server = new ApolloServer({
    typeDefs,
    resolvers
});

server.listen().then(({ url }) => {
    console.log(`  Server ready at ${url}`);
});

在GraphQL游乐场中使用的查询：

{
  companies{
    organisasjonsnummer
  }
}

从GraphQL Playground收到错误：

{
  "errors": [
    {
      "message": "Cannot return null for non-nullable field Query.companies.",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "companies"
      ],
      "extensions": {
        "code": "INTERNAL_SERVER_ERROR",
        "exception": {
          "stacktrace": [
            "Error: Cannot return null for non-nullable field Query.companies.",
            "    at completeValue (F:\\apollo-datasource-rest-example\\node_modules\\graphql\\execution\\execute.js:573:13)",
            "    at F:\\apollo-datasource-rest-example\\node_modules\\graphql\\execution\\execute.js:505:16",
            "    at process._tickCallback (internal/process/next_tick.js:68:7)"
          ]
        }
      }
    }
  ],
  "data": null
}

Answer 1

因为从该链接返回的JSON没有一个名为“ results”的字段，所以对于companies根查询，将解析为null，但是由于其模式定义为[Company!]!。

您应该根据该链接返回的JSON结构，从此解析器返回data.data。

使用Graphql查询API时出现“无法返回null”错误？

1 个答案: