使用AWS Lambda的AWS DynamoDB中的UpdateItem（节点）

Question

我试图使用Lambda（节点）更新DynamoDB中的记录。我可以更改params的结构并获得类似Expected params.ExpressionAttributeValues[':done'] to be a structure的错误，所以我相信它正在与DynamoDB进行通信。

这是PARAMS：

{ 
    "TableName": "test_table", 
    "Key": { 
     "id": { 
      "S": "90c31f23-96e3-4d5d-b08d-95aafb9bed2e" 
     } 
    }, 
    "UpdateExpression": "SET done = :done", 
    "ExpressionAttributeValues": { 
     ":done": { 
      "S": "t" 
     } 
    }, 
    "ReturnValues": "UPDATED_NEW" 
} 

从那里它只是超时，所以很难知道问题是什么。

这是完整的lambda函数：

var aws = require('aws-sdk'); 
var dynamodb = new aws.DynamoDB({ 
    apiVersion: '2012-08-10', 
    accessKeyId: 'xxx', 
    secretAccesskey: 'xxx', 
    region: 'us-west-2' 
}) 

exports.handler = (event, context, callback) => { 
    console.log('Incoming: ', event); 

    var table = "test_table"; 

    event.Records.forEach((record) => { 
     console.log('DynamoDB Record: %j', record.dynamodb); 

     var params = { 
     TableName: table, 
     Key: { 
      "id": record.dynamodb.Keys.id 
     }, 
     UpdateExpression: "SET done = :done", 
     ExpressionAttributeValues: { 
      ":done": { "S": "t" } 
     }, 
     ReturnValues: "UPDATED_NEW" 
     }; 

     console.log("params: %j", params); 

     dynamodb.updateItem(params, function(err, data) { 
     if (err) console.log("Unable to update item. Error: ", JSON.stringify(err, null, 2)); 
     else console.log("Updated item succeeded: ", JSON.stringify(data, null, 2)); 
     }); 
    }); 
    callback(null, "Successfully processed ${event.Records.length} records."); 
}; 

Answer 1

根据文档，你得有一个文档的客户端，并细化流量控制..

var aws = require('aws-sdk'); 
var dynamodb = new aws.DynamoDB({ 
    apiVersion: '2012-08-10', 
    accessKeyId: 'xxx', 
    secretAccesskey: 'xxx', 
    region: 'us-west-2' 
}) 

exports.handler = (event, context, callback) => { 
    console.log('Incoming: ', event); 

    var table = "test_table"; 
    var docClient = new dynamodb.DocumentClient() 

    function async(record, next) { 
     var params = { 
      TableName: table, 
      Key: { 
       "id": record.dynamodb.Keys.id 
      }, 
      UpdateExpression: "SET done = :done", 
      ExpressionAttributeValues: { 
       ":done": { "S": "t" } 
      }, 
      ReturnValues: "UPDATED_NEW" 
     }; 

     console.log("params: %j", params); 

     docClient.updateItem(params, function(err, data) { 
      if (err) console.log("Unable to update item. Error: ", JSON.stringify(err, null, 2)); 
      else console.log("Updated item succeeded: ", JSON.stringify(data, null, 2)); 
      next() // modify for err handling 
     }); 
    } 
    function final() { callback(null, "Successfully processed ${event.Records.length} records."); } 

    var results = []; 

    event.Records.forEach(function(item) { 
     async(item, function(){ 
      results.push(true); 
      if(results.length == event.Records.length) final(); 
     }); 
    }); 
};