How to do nested search with custom variable in ealsticsearch using nodejs? - node.js

This is my data saved in elastic search:
{
index: productName,
type: 'users',
body: {
name:'xyz',
subject:{
12:{
id:12,
name:Maths
count:3
},
13:{
id:13,
name:Physics
count:7
}
}
}
}
Is There a way to somehow search and get total number of users whose count in maths is greater than 0. Where 12 will be in a variable say subject_id.
I tried searching in the docs but coudn't find any one example to use.
I am new to elastic search any help would be appreciated thanks.

Create an object first, like this:
var queryObj = {
"query":{
"range":{
}
}
};
queryObj.query.range['subjects.'+data.subject_id+'.opened']={
"gte":1
};
then pass this object in the body of elastic search like this
elasticClient.search({
index: indexName,
type: type,
body: {
queryObj
}
}).then(promiseFunc)

Related

Storing and querying JSON arrays in Redisjson with nodejs

What I was hoping to do was store an array of objects using RedisJSON very simply and then query that array.
I have something similar to this:
const data = [
{
_id: '63e7d1d85ad7e2f69df8ed6e',
artist: {
genre: 'rock',
},
},
{
_id: '63e7d1d85ad7e2f69df8ed6f',
artist: {
genre: 'metal',
},
},
{
_id: '63e7d1d85ad7e2f69df8ed6g',
artist: {
genre: 'rock',
},
},
]
then I can easily store and retrieve this:
await redisClient.json.set(cacheKey, '$', data)
await redisClient.json.get(cacheKey)
works great. but now I want to also query this data, I've tried creating an index as below:
await redisClient.ft.create(
`idx:gigs`,
{
'$.[0].artist.genre': {
type: SchemaFieldTypes.TEXT,
AS: 'genre',
},
},
{
ON: 'JSON',
PREFIX: 'GIGS',
}
)
and when I try and search this index what I expect is it to return the 2 documents with the correct search filter, but instead it always returns the entire array:
const searchResult = await redisClient.ft.search(`idx:gigs`, '#genre:(rock)')
produces:
{
total: 1,
documents: [
{ id: 'cacheKey', value: [Array] }
]
}
I can't quite work out at which level I'm getting this wrong, but any help would be greatly appreciated.
Is it possible to store an array of objects and then search the nested objects for nested values with RedisJSON?
The Search capability in Redis stack treats each key containing a JSON document as a separate search index entry. I think what you are doing is perhaps storing your whole array of documents in a single Redis key, which means any matches will return the document at that key which contains all of your data.
I would suggest that you store each object in your data array as its own key in Redis. Make sure that these will be indexed by using the GIGS prefix in the key name, for example GIGS:63e7d1d85ad7e2f69df8ed6e and GIGS:63e7d1d85ad7e2f69df8ed6f.
You'd want to change your index definition to account for each document being an object too so it would look something like this:
await redisClient.ft.create(
`idx:gigs`,
{
'$.artist.genre': {
type: SchemaFieldTypes.TEXT,
AS: 'genre',
},
},
{
ON: 'JSON',
PREFIX: 'GIGS:',
}
)
Note I also updated your PREFIX to be GIGS: not GIGS - this isn't strictly necessary, but does stop your index from accidentally looking at other keys in Redis whose name begins GIGS<whatever other characters>.

searching for words that has space in Elastic search

I have a problem in searching that has spaces in my fields with Elastic search.
const body = {
query: {
wildcard: {
name: `${query}*`
}
}
}
Lets say I am searching the name of the cities. When I search "Los", It searches all cities that has substring "los" in it.
But when I search as "Los ang", it doesnt show "Los angeles".
After trying many other way, finally managed to get the result I wanted but still dont know whether this is the right way without wildcard.
const body = {
size: 500,
from: 0,
query: {
query_string: {
fields: ["name"],
query: `${query}*`,
default_operator: "AND"
}
}
}

Sails.js - Get an object (model) using multiple join

I am new to node.js and newer to Sails.js framework.
I am currently trying to work with my database, I don't understand all the things with Sails.js but I manage to do what I want step by step. (I am used to some PHP MVC frameworks so it is not too difficult to understand the structure.)
Here I am trying to get a row from my database, using 2 JOIN clause. I managed to do this using SQL and the Model.query() function, but I would like to do this in a "cleaner" way.
So I have 3 tables in my database: meta, lang and meta_lang. It's quite simple and a picture being better than words, here are some screenshots.
meta
lang
meta_lang
What I want to do is to get the row in meta_table that match with 'default' meta and 'en' lang (for example).
Here are Meta and Lang models (I created them with sails generate model command and edited them with what I needed):
Meta
module.exports = {
attributes: {
code : { type: 'string' },
metaLangs:{
collection: 'MetaLang',
via: 'meta'
}
}
};
Lang
module.exports = {
attributes: {
code : { type: 'string' },
metaLangs:{
collection: 'MetaLang',
via: 'lang'
}
}
};
And here is my MetaLang model, with 3 functions I created to test several methods. The first function, findCurrent, works perfectly, but as you can see I had to write SQL. That is what I want to avoid if it is possible, I find it more clean (and I would like to use Sails.js tools as often as I can).
module.exports = {
tableName: 'meta_lang',
attributes: {
title : { type: 'string' },
description : { type: 'text' },
keywords : { type: 'string' },
meta:{
model:'Meta',
columnName: 'meta_id'
},
lang:{
model:'Lang',
columnName: 'lang_id'
}
},
findCurrent: function (metaCode, langCode) {
var query = 'SELECT ml.* FROM meta_lang ml INNER JOIN meta m ON m.id = ml.meta_id INNER JOIN lang l ON l.id = ml.lang_id WHERE m.code = ? AND l.code = ?';
MetaLang.query(query, [metaCode, langCode], function(err, metaLang) {
console.log('findCurrent');
if (err) return console.log(err);
console.log(metaLang);
// OK this works exactly as I want (I would have prefered a 'findOne' result, only 1 object instead of an array with 1 object in it, but I can do with it.)
});
},
findCurrentTest: function (metaCode, langCode) {
Meta.findByCode(metaCode).populate('metaLangs').exec(function(err, metaLang) {
console.log('findCurrentTest');
if (err) return console.log(err);
console.log(metaLang);
// I get what I expected (though not what I want): my meta + all metaLangs related to meta with code "default".
// What I want is to get ONE metaLang related to meta with code "default" AND lang with code "en".
});
},
findCurrentOthertest: function (metaCode, langCode) {
MetaLang.find().populate('meta', {where: {code:metaCode}}).populate('lang', {where: {code:langCode}}).exec(function(err, metaLang) {
console.log('findCurrentOthertest');
if (err) return console.log(err);
console.log(metaLang);
// Doesn't work as I wanted: it gets ALL the metaLang rows.
});
}
};
I also tried to first get my Meta by code, then my Lang by code, and MetaLang using Meta.id and Lang.id . But I would like to avoid 3 queries when I can have only one.
What I'm looking for would be something like MetaLang.find({meta.code:"default", lang.code:"en"}).
Hope you've got all needed details, just comment and ask for more if you don't.
Do you know what populate is for ? its for including the whole associated object when loading it from the database. Its practically the join you are trying to do, if all you need is row retrieval than quering the table without populate will make both functions you built work.
To me it looks like you are re-writing how Sails did the association. Id suggest giving the Associations docs another read in Sails documentation: Associations. As depending on your case you are just trying a one-to-many association with each table, you could avoid a middle table in my guess, but to decide better id need to understand your use-case.
When I saw the mySQL code it seemed to me you are still thinking in MySQL and PHP which takes time to convert from :) forcing the joins and middle tables yourself, redoing a lot of the stuff sails automated for you. I redone your example on 'disk' adapter and it worked perfectly. The whole point of WaterlineORM is to abstract the layer of going down to SQL unless absolutely necessary. Here is what I would do for your example, first without SQL just on a disk adapter id create the models :
// Lang.js
attributes: {
id :{ type: "Integer" , autoIncrement : true, primaryKey: true },
code :"string"
}
you see what i did redundantly here ? I did not really need the Id part as Sails does it for me. Just an example.
// Meta.js
attributes: {
code :"string"
}
better :) ?
// MetaLang.js
attributes:
{
title : "string",
desc : "string",
meta_id :
{
model : "meta",
},
lang_id :
{
model : "lang",
}
}
Now after simply creating the same values as your example i run sails console type :
MetaLang.find({meta_id : 1 ,lang_id:2}).exec(function(er,res){
console.log(res);
});
Output >>>
sails> [ { meta_id: 1,
lang_id: 2,
title: 'My blog',
id: 2 } ]
Now if you want to display what is meta with id 1 and what is lang with id 2, we use populate, but the referencing for join/search is just as simple as this.
sails> Meta_lang.find({meta_id : 1 ,lang_id:2}).populate('lang_id').populate('meta_id').exec(function(er,res){ console.log(res); });
undefined
sails> [ {
meta_id:
{ code: 'default',
id: 1 },
lang_id:
{ code: 'En',
id: 2 },
title: 'My blog',
id: 2 } ]
At this point, id switch adapters to MySQL and then create the MySQL tables with the same column names as above. Create the FK_constraints and voila.
Another strict policy you can add is to set up the 'via' and dominance on each model. you can read more about that in the Association documentation and it depends on the nature of association (many-to-many etc.)
To get the same result without knowing the Ids before-hand :
sails> Meta.findOne({code : "default"}).exec(function(err,needed_meta){
..... Lang.findOne({code : "En"}).exec(function(err_lang,needed_lang){
....... Meta_lang.find({meta_id : needed_meta.id , lang_id : needed_lang.id}).exec(function(err_all,result){
......... console.log(result);});
....... });
..... });
undefined
sails> [ { meta_id: 1,
lang_id: 2,
title: 'My blog',
id: 2 } ]
Have you tried:
findCurrentTest: function (metaCode, langCode) {
Meta.findByCode(metaCode).populate('metaLangs', {where: {code:langCode}}).exec(function(err, metaLang) {
console.log('findCurrentTest');
if (err) return console.log(err);
console.log(metaLang);
});
},

How do I limit the properties of a query based of a common subproperty?

Given the schema:
{
_id: ObjectID,
city:
{ units:
{ abc: {},
def: { tuid : String },
...
xxx: { tuid : String }
}
}
I would like to return, for a particular _id, all the properties of units who's subproperty tuid is, for example, 123.
I have searched for information about this but array operations keep popping up instead of what I need.
Thank you.

How to match any location from a given list of coordinates in MongoDB?

I am currently using MongoDB with node.js and Mongoose to perform geospatial searches.
I'm working with the following documents and collections:
waypoints are documents that contain location and other metadata (just is there, not otherwise relevant for this question)
targets collection contains 1...n waypoints
sources collection contains exactly 1 waypoint
Simple example of what these documents may look like:
// Target
{
waypoints: [
{
loc: [61.24, 22.24],
time: 0
},
{
loc: [61.25, 22.24],
time: 1
},
{
loc: [61.26, 22.24],
time: 2
},
]
}
// Source
{
waypoint: {
loc: [61.24, 22.24],
time: 0
}
}
So my question is this:
Given that we have a specific target document (like the one above), what is the easiest way to find all source documents near (within distance of MAX_DISTANCE) any of the given waypoints in the target?
Matching for single waypoint is trivial:
Source.find({
'from.loc': {
$within: {
$center: [target.waypoints[0].loc, MAX_DISTANCE],
$uniqueDocs: true
}
}
})
However I'm struggling to find the solution of how to match any of the given waypoints. For instance the following query doesn't work:
Source.find({
$or: [
{
'waypoint.loc': {
$within: {
$center: [target.waypoints[0].loc, MAX_DISTANCE],
$uniqueDocs: true
}
}
},
{
'waypoint.loc': {
$within: {
$center: [target.waypoints[1].loc, MAX_DISTANCE],
$uniqueDocs: true
}
}
},
{
'waypoint.loc': {
$within: {
$center: [target.waypoints[2].loc, MAX_DISTANCE],
$uniqueDocs: true
}
}
}
]
})
Any ideas why this doesn't work and what would be the alternative?
All help is much appreciated!
P.S. I'm using MongoDB v2.0.5, Mongoose 2.7.4 & node v0.8.7
$or queries are implemented as separate queries internally anyway, so aside from a lack of elegance, something like the following works w/o too much bloat (with a little help from the underscore library):
var nearSources = {}, count = target.waypoints.length;
target.waypoints.forEach(function (waypoint) {
Source.find({
'waypoint.loc': {
$within: {
$center: [waypoint.loc, MAX_DISTANCE],
$uniqueDocs: true
}
}
}, function (err, sources) {
if (sources) {
// Add the unique sources to the nearSources object by _id.
sources.forEach(function (source) {
nearSources[source._id] = source;
});
}
if (--count === 0) {
// Done! Convert nearSources to an array of source docs.
nearSources = _.values(nearSources);
}
});
});

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