CODEWITHSUNDEEP
node.jsamazon-web-servicesamazon-dynamodbaws-lambda
Shan
Shan

Reputation: 43

AWS lambda function retrieving dynamodb data as a error message

I have written simple Lambda function to scan data from dynamodb, but data is getting retrieved with error message tag and lambda function shows message as execution failed 

    var AWS = require('aws-sdk');
    var DOC = require("dynamodb-doc");
    var dynamo = new DOC.DynamoDB();
    exports.handler = function (event, context, callback) {

     var params = {
        TableName: "Movies",
       // ProjectionExpression: "#yr, Movie",
        FilterExpression: "#yr = :thisyear",
        ExpressionAttributeNames: {
        "#yr": "year",
    },
    ExpressionAttributeValues: {
         ":thisyear" : 2009
    }       
};

  dynamo.scan(params, function(err, data){
          if (err){
        callback("error occoured");
          }
          else{
        callback(JSON.stringify(data.Items));
          }          
  });
  };

Result 

{
  "errorMessage": "[{\"year\":2009,\"Movie\":\"Jab tak hai jaan\"}]"
}

Upvotes: 0

Views: 453

Answers (1)

Manoj
Manoj

Reputation: 2452

nodejs callback are typically error-first callbacks. It means that the first parameter is the error message and the second parameter is the result. So when returning the result you need to pass null as the first argument. eg: callback(null, JSON.stringify(data.Items));

Please refer this article

Upvotes: 1

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