为什么出现错误：无法查询类型“query”上的字段xx？

Question

虽然我在GraphiQL上测试成功后从GraphiQL工具中复制并粘贴了GraphiQL查询，但当我在reactJS应用程序内的Apollo客户端中尝试该查询时，该查询返回了一个错误：

[GraphQL error]: Message: Cannot query field "allStudents" on type "Query"., Location: [object Object], Path: undefined

下面是我的实现：

const link = createHttpLink({
  uri: 'http://localhost:8000/graphql',
  fetchOptions: { method: "POST" }
});

const client = new ApolloClient({
  link: link 
});

const GET_STUDENTS = gql`
query getStudents($schoolID: Int!){
  allStudents(schoolId: $schoolID){
    pickUpLat
    pickUpLng
  }
}
`;

client
  .query({
    query: GET_STUDENTS,
    variables: { schoolID: 1 }
  })
  .then(result => console.log(result));

会有什么问题吗？以下是我预期的正确回应：

{
  "data": {
    "allStudents": [
      {
        "pickUpLat": 31.9752942479727,
        "pickUpLng": 35.8438429235775
      },
      {
        "pickUpLat": 31.9754545979993,
        "pickUpLng": 35.8437478537235
      }
    ]
  }
}

{"operationName":"getStudents","variables":{"schoolID":1},"query":"query getStudents($schoolID: Int) {\n  allStudents(schoolId: $schoolID) {\n    pickUpLat\n    pickUpLng\n    __typename\n  }\n}\n"}

{"query":"query getStudents($schoolID: Int!){\n  allStudents(schoolId: $schoolID){\n    pickUpLat\n    pickUpLng\n  }\n}","variables":{"schoolID":1},"operationName":"getStudents"}

所以，他们几乎一模一样，有什么想法吗？

Answer 1

在我的例子中,我定义了一个不需要任何参数的查询,它将返回一个对象数组：

myBasicQuery: [BasicAnswer]

type BasicAnswer {
  name String
  phone String
}

当我声明类型\“BasicAnswer\”上的字段\“BasicAnswer\”时，我得到了一个错误:无法查询它：

query myBasicQuery {
  BasicAnswer {
      name
      phone
  }
}

只保留BasicAnswer的字段就可以解决这个问题：

query myBasicQuery {
    name
    phone
}