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.
Related
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>.
I am having a problem searching for a key of a nested object.
I have search criteria object that may or may not have certain fields I'd like to search on.
The way I'm solving this is to use conditional statements to append to a "match criteria" object that gets passed to the aggregate $match operator. it works well until I need to match to something inside a nested object.
Here is a sample document structure
{
name: string,
dates: {
actived: Date,
suspended: Date
},
address : [{
street: string,
city: string,
state: string,
zip: string
}]
};
My criteria object is populated thru a UI and passed a JSON that looks similar to this:
{
"name": "",
"state": ""
}
And although I can explicitly use "dates.suspended" without issue -
when I try to append address.state to my search match criteria - I get an error.
module.exports.search = function( criteria, callback )
let matchCriteria = {
"name": criteria.name,
"dates.suspended": null
};
if ( criteria.state !== '' ) {
// *** PROBLEM HAPPENS HERE *** //
matchCriteria.address.state = criteria.state;
}
User.aggregate([
{ "$match": matchCriteria },
{ "$addFields": {...} },
{ "$project": {...} }
], callback );
}
I get the error:
TypeError: Cannot set property 'state' of undefined
I understand that I'm specifying 'address.state' when 'address' doesn't exist yet - but I am unclear what my syntax would be surely it woulnd't be matchCriteria['address.state'] or "matchCriteria.address.state"
Is there a better way to do conditional filtering?
For search in Nested Object, You have to use unwind
A query that help you :
//For testing declare criteria as const
let criteria = {name : 'name', 'state' : 'state'};
let addressMatch = {};
let matchCriteria = {
"name": criteria.name,
"dates.suspended": null
};
if ( criteria.state) {
addressMatch = { 'address.state' : criteria.state };
}
db.getCollection('user').aggregate([{
$match :matchCriteria,
},{$unwind:'$address'},
{$match : addressMatch}
])
Firstly check for address, and then access the property as shown:
if(matchCriteria['address']) {
matchCriteria['address']['state'] = criteria['state'];
}
else {
//otherwise
}
This should fix it:
matchCriteria['address.state'] = criteria.state;
What I want to do:
Whenever I add a new item to the collection (in my case a game), it will have a incremented "index"-like value (in my case I'm naming it index too).
My games collection should looks like:
[
{ "index":0, ... data }
{ "index":1, ... data }
{ "index":2, ... data }
]
The term is so hard to search. I always end up with:
$inc for update. Not this, I want to have incremented number on create.
Schema.index does look like what I want, but somehow it doesn't work at all:
const gameModel = new Schema({
index: {
type: Number,
default: 0
},
players: [{
name: String,
score: Number
}]
}, {
timestamps: {
createdAt: 'date'
}
});
gameModel.index({
index: 1
});
With this I always get index: 0. If I turn off default no index is created.
What do I do now? (I would prefer to keep the _id intact)
You can use a npm package named mongoose-auto-increment which provides this functionality. It is also very easy and well documented
I want to create a String + number every time a value is inserted on database (the number must be autoincrement).
Is it possible to do in Schema? Or do I need to do that before the value's inserted on database?
'question' -> String followed by an autoincrement number
var random = [{
question: 'question1'
},{
question: 'question2'
},{
question: 'question3'
},{
question: 'question4'
}];
const RandomSchema = new Schema({
question: {
type: String,
unique: true
}
})
Autoincrement fields in Mongodb, don't work exactly the same way that they do in an RDBMS. There is a lot more overhead involved. Never the less, creating an auto field is a solved problem. There is also a third party mongoose-autoincrement package that make it a lot easier.
Extending, from that. Your problem is a solved problem too. Because
the string part will always be the same
Simply use string concatenation to prepend 'question' to the auto increment field at display time.
Here is what I implemented with one of the approaches #e4c5 pointed out, without the use of a third-party package.
Define add.js as below:
db.counters.insert(
{
_id: "itemid",
seq: 0
}
)
function getNextSequence(id) {
var ret = db.counters.findAndModify(
{
query: { _id: id },
update: { $inc: { seq: 1 } },
new: true
}
);
return ret.seq;
}
db.randoms.insert(
{
question: "question"+getNextSequence("itemid"),
}
)
db.randoms.insert(
{
question: "question"+getNextSequence("itemid"),
}
)
After starting a mongod instance, do mongo < add.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)