DynamoDB con NodeJS

per prima cosa si installa nel progetto AWS SDK per NodeJS con

npm install aws-sdk
si lancia poi DynamoDB in locale come visto qui 

per fare  il deploy sui server Amazon del DB si deve decommentare la riga evidenziata in giallo

=========================================================
var AWS = require("aws-sdk");

AWS.config.update({region: "us-west-1",endpoint: "http://localhost:8000"});

// per fare il deploy su DynamoDB sui server Amazon
//AWS.config.update({endpoint: "https://dynamodb.us-west-2.amazonaws.com"});

var dynamodb = new AWS.DynamoDB();

var params = {
    TableName : "Informazioni",
    KeySchema: [
        { AttributeName: "indice", KeyType: "HASH"},  //Partition key
        { AttributeName: "title", KeyType: "RANGE" }  //Sort key
    ],
    AttributeDefinitions: [
        { AttributeName: "indice", AttributeType: "N" },
        { AttributeName: "title", AttributeType: "S" }
    ],
    ProvisionedThroughput: {
        ReadCapacityUnits: 10,
        WriteCapacityUnits: 10
    }
};



dynamodb.createTable(params, function(err, data) {
    if (err) {
        console.error("Unable to create table. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("Created table. Table description JSON:", JSON.stringify(data, null, 2));
    }
});


//////////// INSERT ////////////////////////
var docClient = new AWS.DynamoDB.DocumentClient();
var table = "Informazioni";
var indice = 2015;
var title = "Il nome della rosa";

var params = {
    TableName:table,
    Item:{
        "indice": indice,
        "title": title,
    }
};

console.log("Adding a new item...");
docClient.put(params, function(err, data) {
    if (err) {
        console.error("Unable to add item. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("Added item:", JSON.stringify(data, null, 2));
    }
});

//////////// QUERY ////////////////////////
var params = {
    TableName : table,
    KeyConditionExpression: "#yr = :yyyy",
    ExpressionAttributeNames:{
        "#yr": "indice"
    },
    ExpressionAttributeValues: {
        ":yyyy": 2015
    }
};

docClient.query(params, function(err, data) {
    if (err) {
        console.error("Unable to query. Error:", JSON.stringify(err, null, 2));
    } else {
        console.log("Query succeeded.");
        data.Items.forEach(function(item) {
            console.log(" -", item.indice + ": " + item.title);
        });
    }
});



//////////// DELETE ITEM ////////////////////////
var params = {
    TableName:table,
    Key:{
        "indice": indice,
        "title": title
    },
    ConditionExpression:"indice <= :val",
    ExpressionAttributeValues: {
        ":val": 2016
    }
};

console.log("Attempting a conditional delete...");
docClient.delete(params, function(err, data) {
    if (err) {
        console.error("Unable to delete item. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("DeleteItem succeeded:", JSON.stringify(data, null, 2));
    }
});


var params = {
    TableName : table
};

//////////// DELETE TABLE////////////////////////

dynamodb.deleteTable(params, function(err, data) {
    if (err) {
        console.error("Unable to delete table. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("Deleted table. Table description JSON:", JSON.stringify(data, null, 2));
    }
});