Flutter aws amplify 在调用 graphql 时不返回数据 api

Question

单击按钮时，我已编程调用连接到 Lambda 函数的 graphql api，该函数正在从 dynamodb table 中提取数据。查询不会产生任何错误，但也不会给我任何结果。我还检查了 cloudwatch 日志，但没有看到任何被调用函数的痕迹。不确定我在这里犯的粗心错误。

这是我的 api

void findUser() async {
  try {
    String graphQLDocument = '''query getUserById($userId: ID!) {
    getUserById(userId: $id) {
    id
    name
  }
}''';

    var operation = Amplify.API.query(
        request: GraphQLRequest<String>(
            document: graphQLDocument,
            variables: {'id': 'USER-14160000000'}));

    var response = await operation.response;
    var data = response.data;

    print('Query result: ' + data);
  } on ApiException catch (e) {
    print('Query failed: $e');
  }
}

这是我的 lambda 函数 -

const getUserById = require('./user-queries/getUserById');
exports.handler = async (event) => {
   var userId = event.arguments.userId;
   var name = event.arguments.name;
   var avatarUrl = event.arguments.avatarUrl;
   //console.log('Received Event - ', JSON.stringify(event,3));
   console.log(userId);
   switch(event.info.fieldName) {
       case "getUserById": 
           return getUserById(userId);
   }
 };

const AWS = require('aws-sdk');
const docClient = new AWS.DynamoDB.DocumentClient({region: 'ca-central-1'});

async function getUserById(userId) {
    const params = {
        TableName:"Bol-Table",
        KeyConditionExpression: 'pk = :hashKey and sk = :sortKey',
        ExpressionAttributeValues: {
            ':hashKey': userId,
            ':sortKey': 'USER'
        }
    };
    try {
        const Item = await docClient.query(params).promise();
        console.log(Item);
        return { 
            id: Item.Items[0].pk, 
            name: Item.Items[0].details.displayName,
            avatarUrl: Item.Items[0].details.avatarUrl,
            createdAt: Item.Items[0].details.createdAt,
            updatedAt: Item.Items[0].details.updatedAt
        };
    } catch(err) {
        console.log("BOL Error: ", err);
    }
 }
 
 module.exports = getUserById;

单击按钮后我得到了这个

Answer 1

您的 flutter 代码工作正常，但在 aws 的 lambda 中返回空白字符串“”以不打印任何内容

Answer 2

将我的评论移至答案：

能否尝试将 graphQLDocumnet 更改为

String graphQLDocument = '''query getUserById($id: ID!) {
     getUserById(userId: $id) { 
            id
            name
     }
}''';

您的变量是 $userId，然后是 $id。尝试在变量对象中的两个地方都调用它 $id。

Flutter aws amplify 在调用 graphql 时不返回数据 api

Flutter aws amplify not returning data when calling graphql api

amazon-web-services

flutter

graphql

aws-amplify