I am trying to say:
select * from myTable where pkName in ('john', 'fred', 'jane')
but there doesn't seem to be a native way to feed a list of items in an array. I have my query working and retrieving values for a single primary key but want to be able to pass in multiple ones. It seems this isn't possible from looking at the DynamoDb page in the console but is there a good workaround? Do I just have multiple OR in my KeyConditionExpression and a very complex ExpressionAttributeValues?
I'm referencing this page:
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html
And using code based on the following (which can be found at the address below):
var params = {
ExpressionAttributeValues: {
':s': {N: '2'},
':e' : {N: '09'},
':topic' : {S: 'PHRASE'}
},
KeyConditionExpression: 'Season = :s and Episode > :e',
ProjectionExpression: 'Title, Subtitle',
FilterExpression: 'contains (Subtitle, :topic)',
TableName: 'EPISODES_TABLE'
};
https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-query-scan.html
You are looking for the batchGetItem function, documented here.
You can also use DocumentClient and batchGet.
const AWS = require('aws-sdk');
const dbClient = new AWS.DynamoDB.DocumentClient({ region: 'ap-south-1' });
exports.handler = (event, context, callback) => {
var cartItems=JSON.parse(event.body);
let scanningtable = {
RequestItems: {
COOLERS : {
Keys: [
{
"ITEM_ID": 379
},
{
"ITEM_ID": 376
}
],
ProjectionExpression: "ITEM_ID, #N,CATEGORY, SUB_CATEGORY, BRAND, SELL_RATE",
ExpressionAttributeNames: {
"#N": "NAME"
},
}
}
};
dbClient.batchGet(scanningtable, function (err, data) {
if (err) {
callback(err, null);
} else {
var response = {
"statusCode": 200,
"headers": {
"Access-Control-Allow-Origin": "*"
},
"body": JSON.stringify(data),
};
callback(null, response);
}
});
};
Related
Using this node-ews package, I can send email, but I haven't been able to find a good example of how to read mails from the Inbox folder and get the email's text and attachments.
I've read the Microsoft documentation, such as this one: https://learn.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-work-with-exchange-mailbox-items-by-using-ews-in-exchange#get-an-item-by-using-the-ews-managed-api, but the examples are in C#, C++, or VB.
However, I would like to use Nodejs for this.
**I have found a best way extract every content using mailparser. see bellow
// At first Read emails from Inbox
const EWS = require('node-ews');
const simpleParser = require('mailparser').simpleParser;
// exchange server connection info
const ewsConfig = {
username: 'username',
password: 'password',
host: 'hostname'
};
const options = {
rejectUnauthorized: false,
strictSSL: false
};
// initialize node-ews
const ews = new EWS(ewsConfig, options);
var ewsFunction = 'FindItem';
var ewsArgs = {
'attributes': {
'Traversal': 'Shallow'
},
'ItemShape': {
't:BaseShape': 'Default'
},
'ParentFolderIds' : {
'DistinguishedFolderId': {
'attributes': {
'Id': 'inbox'
}
}
}
};
// Itreate over all the emails and store Id and ChangeKey.
ews.run(ewsFunction, ewsArgs, ewsSoapHeader)
.then(result => {
// Iterate over the result and extract Id and ChangeKey of the messages and pass those to GetItem function to read messages
})
// For reading individual messages returned by FindItem (using Id and ChangeKey)
var ewsFunction = 'GetItem';
var ewsArgs = {
'ItemShape': {
'BaseShape': 'Default',
'AdditionalProperties': {
'FieldURI': [
{ 'attributes': { 'FieldURI': 'item:MimeContent'}}
]
}
},
'ItemIds': {
'ItemId': {
'attributes': {
'Id': Id,
'ChangeKey': ChangeKey
}
}
}
};
await ews.run(ewsFunction, ewsArgs, ewsSoapHeader)
.then(result => {
// Iterate over the result and extract meesage
const {Message} = result.ResponseMessages.GetItemResponseMessage.Items
let mimeContent = Buffer.from(Message.MimeContent['$value'], 'base64').toString('binary');// decode mime content
simpleParser(mimeContent).then(async function (mail) {
console.log("mail")
console.log(mail.attachments)
console.log(mail.headers.get('message-id'))
console.log(mail.headers.get('references'))
console.log(mail.headers.get('in-reply-to'))
console.log({
// text: mail.text,
// html: mail.html ? mail.html.replace(/<meta([^>]+)>/g, "") : "",
from: (mail.from) ? mail.from.value.map(item => item.address) : [],
to: (mail.to) ? mail.to.value.map(item => item.address) : [],
cc: (mail.cc) ? mail.cc.value.map(item => item.address) : [],
bcc: (mail.bcc) ? mail.bcc.value.map(item => item.address) : [],
messageId: mail.messageId,
subject: mail.subject
})
}).catch((err) => {
console.log("err")
console.log(err)
})
})
Here you will get the full parsed mail contents with attachments. Happy Coding!!!
I am trying to use Watson translator service from my node.js app through the API documentation from IBM https://www.ibm.com/watson/developercloud/alchemyvision/api/v1/#apiexplorer
var request = require("request");
var LanguageTranslatorV3 = require('watson-developer-cloud/language-translator/v3');
var english_message
var languageTranslator = new LanguageTranslatorV3({
version: '2018-05-01',
username: '1234',
password: '1234',
url: 'https://gateway.watsonplatform.net/language-translator/api'
});
function translatorEnglish(message) {
var parameters = {
text: message.text,
model_id: 'es-en'
};
languageTranslator.translate(
parameters,
function(error, response, body) {
if (error)
console.log(error)
else
console.log(JSON.stringify(response, null, 2));
}
);
}
I get the following correct response in logs
{
"translations": [
{
"translation": "Hi."
}
],
"word_count": 1,
"character_count": 4
}
but when i try to extract the output translation value i always get the output as Undefined.
console.log(response.translations.translation); => undefined
Can you please check and let me know if i am doing anything wrong?
Thanks
Try
console.log(response.translations[0].translation); // Hi
This is because translations is an array and has one item at index 0.
{
"translations": [
{
"translation": "Hi."
}
],
"word_count": 1,
"character_count": 4
}
I need to do a join query on firebase using elasticsearch,
can anyone help me?
In particular I have two nodes, in the child node I have a field that is the id of the father node and I would like to have as a result all the fields of the father node.
How do I build my index in the code?
In adding, in my client I use elasticsearchclient,
here is an extract of the code to index a node:
var db = admin.database();
var etest = db.ref(type);
etest.on('child_added', createOrUpdateIndex);
etest.on('child_changed', createOrUpdateIndex);
etest.on('child_removed', removeIndex);
function createOrUpdateIndex(snap) {
client.index(index, type, snap.val(), snap.key)
.on('data', function(data) { console.log('indexed', snap.key + data ); })
.on('error', function(err) { console.log('index error ', err); }).exec();
}
function removeIndex(snap) {
client.deleteDocument(index, type, snap.key, function(error, data) {
if( error ) console.error('failed to delete', snap.key, error);
else console.log('deleted', snap.key);
});
}
And to take query results:
var queue = db.ref("search");
queue.child('request').on('child_added', processRequest);
function processRequest(snap) {
console.log('process...... ');
snap.ref.remove(); // clear the request after we receive it
var data = snap.val();
// Query ElasticSearch
client.search(index, data.type, { "query": { 'query_string': {
"query" : data.query
}}})
.on('data', function(results) {
var res = JSON.parse(results);
console.log(JSON.stringify(res.hits));
console.log("TOTAL " + JSON.stringify(res.hits.total));
queue.child('response/'+snap.key).set(results);
})
.on('error', function(error){ console.log("errore"); }).exec();
}
Thank you in advance
There are two ways to store your data.
First is creating a nested doc. This is helpful if you need to perform search on some of the values and need other info only for the display.
PUT /my_index {
"mappings": {
"yourIndex": {
"properties": {
"yourColumn": {
"type": "nested",
"properties": {
"name": { "type": "string" },
"parentNode": { "type": "string" },
"childNode": { "type": "string" }
}
}
}
}}}
Eg.
'str1', 'parent1', 'child1'
'str2' 'parent1', 'child2'
If you need not maintain any hierarchy,
you can simply create 3 separate columns and store like a flat data.
You can specify parent1 id and search for all the docs in both the cases.
In the below code from MongoDB's course Week 3's Query Operators in the Node.js Driver chapter :
var MongoClient = require('mongodb').MongoClient,
commandLineArgs = require('command-line-args'),
assert = require('assert');
var options = commandLineOptions();
MongoClient.connect('mongodb://localhost:27017/crunchbase', function(err, db) {
assert.equal(err, null);
console.log("Successfully connected to MongoDB.");
var query = queryDocument(options);
var projection = {
"_id": 1,
"name": 1,
"founded_year": 1,
"number_of_employees": 1,
"crunchbase_url": 1
};
var cursor = db.collection('companies').find(query, projection);
var numMatches = 0;
cursor.forEach(
function(doc) {
numMatches = numMatches + 1;
console.log(doc);
},
function(err) {
assert.equal(err, null);
console.log("Our query was:" + JSON.stringify(query));
console.log("Matching documents: " + numMatches);
return db.close();
}
);
});
function queryDocument(options) {
console.log(options);
var query = {
"founded_year": {
"$gte": options.firstYear,
"$lte": options.lastYear
}
};
if ("employees" in options) {
query.number_of_employees = {
"$gte": options.employees
};
}
return query;
}
function commandLineOptions() {
var cli = commandLineArgs([{
name: "firstYear",
alias: "f",
type: Number
}, {
name: "lastYear",
alias: "l",
type: Number
}, {
name: "employees",
alias: "e",
type: Number
}]);
var options = cli.parse()
if (!(("firstYear" in options) && ("lastYear" in options))) {
console.log(cli.getUsage({
title: "Usage",
description: "The first two options below are required. The rest are optional."
}));
process.exit();
}
return options;
}
I'm requiring command-line-args package, which has a method commandLineArgs. All good and fine...
Now, I see that the type of the objects passed to this method is set to Number. We can clearly see that they're Strings.
How is it possible?
From the command-line-args GitHub page:
The type value is a setter function (you receive the output from this), enabling you to be specific about the type and value received.
In other words, passing Number as type allows you to parse the arguments as numbers.
var urlSchema = new Schema ( {
url : String,
visitor : [{name: String,date: Date}],
counter : Number
});
var url = mongoose.model('url',urlSchema);
var domain = blah blah;
var conditions = { url: domain };
var update = { $inc : {counter:1},
$push : { visitor: [{
name: data.username,
date: new Date()
}]
}
};
var options = {upsert: true};
url.update(conditions,update,options,function(err){
if(err){
console.log(err);
}else{
console.log('A domain successfully added to DB');
}
Currently I am using the schema and code above to make an access counter for each page.
It upserts url documents which is counting total access and holding access user info.
so far so good It's working properly.
now I want to add "counter : Number" in visitor array and when the event occurs, if the user is already in visitor array,I want to update that instead of pushing new one.
But I have no idea how to make the 'double upsert' command.
is there anyway to do that?
It may be a bit difficult even impossible perform a query that satisfy your condition. I have reproduced your scenario with following query
url.findOne({'url': 'search.php', 'visitor.name': "JohnDoe"},
function (err, visitor) {
if (visitor) {
url.update(
{
'url': 'search.php', 'visitor.name': "JohnDoe"
},
{
$inc: {'visitor.$.counter': 1, 'counter': 1}
},
function(err, result) {
if (err) {
console.log("Error occured")
} else {
console.log("Success");
}
});
} else {
var conditions = { url: 'search.php' };
var update = { $inc : {counter:1},
$push : { visitor: [{
name: data.username,
date: new Date(),
counter: 0
}]
}
};
var options = {upsert: true};
url.update(conditions,update,options,function(err){
if(err){
console.log(err);
}else{
console.log('A domain successfully added to DB');
}
});
}
}
);
Simple, insert if not exists with counter = 0, update if exists with incrementing counter by 1