Paginate the results of a larger DynamoDB query or scan. This script scans the Failures table in Oregon returning some 3xx odd records as well as a record count and LastEvaluatedKey property. The LastEvaluateKey property holds the failureKey for the last item returned. The script uses that to resume a query query starting with the record followi…

aws_dynamodb_paginate.js

'use strict'

process.env.AWS_SDK_LOAD_CONFIG = true;
process.env.AWS_PROFILE = "development";

const AWS = require('AWS-SDK');

AWS.config.update( { region: "us-west-2"} );

const ddbc = new AWS.DynamoDB.DocumentClient();
let TableName = "Failures";

const p = {
    TableName,
    PageSize: 5    
};

ddbc.scan(p, (error, data) => {
    console.log("Starting Scan...");

    if (error) {
        console.log(error);
    } else {
        if (typeof data.LastEvaluatedKey != "undefined") {
            console.log("Last Item: %s", data.LastEvaluatedKey.failureKey);
            console.log("Records Retrieved: %s", data.Count);
            scanIt(TableName, p, data.LastEvaluatedKey);
        }
    }
});

const scanIt = (TableName, Parameters, ExclusiveStartKey) => {
    p.ExclusiveStartKey = ExclusiveStartKey;
    ddbc.scan(p, (error, data) => {
        if (error) {
            console.log(error);
        } else {
            if (typeof data.LastEvaluatedKey != "undefined") {
                console.log("Last Item: %s", data.LastEvaluatedKey.failureKey);
                console.log("Records Retrieved: %s", data.Count);
                scanIt(TableName, Parameters, data.LastEvaluatedKey);
            } else {
                console.log("Records Retrieved: %s", data.Count);
                console.log("Complete...");
            }
        }
    });
}