I have a collection with data like this:
[{
_id: 1,
address: '1/23 Fake Street'
},
{
_id: 2,
address: '5/20 Whatever Lane'
},
{
_id: 3,
address: '10 Foo Avenue'
}]
I'd like to perform a Mongo bulk update query, which does the following:
Transforms the address field to lowercase
Creates a new field, 'buildingAddress', which splits an address at the slash (if present, as with the first two items) and uses the text after it to populate the new field
In Node, I'd do something like this:
const cursor = db.items.find({});
for await (const item of cursor) {
try {
await pageMapper(item);
} catch (e) {
console.error(e);
}
}
async function pageMapper(item){
const newAddress = item.address.toLowerCase()
const buildingAddress = newAddress.split('/ ')[1];
return db.items.updateOne(item._id, {
$set: {
address: newAddress,
buildingAddress
}
})
}
I'm wondering if there's a way to do this in the MongoDB shell itself, passing in a function to db.collection.update? Or should I stick to the node driver for doing more complex update operations?
If you are using MongoDB 4.2+, you can use aggregation or the pipeline form of update to accomplish that.
$toLower converts a string to lower case
$split to split the field
$slice or $arrayElemAt to pick the element(s) to keep
One possible way to do that with update:
db.items.updateMany({},[
{$addFields:{
address:{$toLower:"$address"}
}},
{$addFields:{
buildingAddress:{
$arrayElemAt:[
{$split:["$address","/"]},
-1
]
}
}}
])
I have a database like this:
[
{
"universe":"comics",
"saga":[
{
"name":"x-men",
"characters":[
{
"character":"wolverine",
"picture":"618035022351.png"
},
{
"character":"cyclops",
"picture":"618035022352.png"
}
]
}
]
},
{
"universe":"dc",
"saga":[
{
"name":"spiderman",
"characters":[
{
"character":"venom",
"picture":"618035022353.png"
}
]
}
]
}
]
and with this code I manage to update one of the objects in my array. specifically the object where character: wolverine
db.mydb.findOneAndUpdate({
"universe": "comics",
"saga.name": "x-men",
"saga.characters.character": "wolverine"
}, {
$set: {
"saga.$[].characters.$[].character": "lobezno",
"saga.$[].characters.$[].picture": "618035022354.png",
}
}, {
new: false
}
)
it returns all my document, I need ONLY the document matched
I would like to return the object that I have updated without having to make more queries to the database.
Note
I have been told that my code does not work well as it should, apparently my query to update this bad, I would like to know how to fix it and get the object that matches these search criteria.
In other words how can I get this output:
{
"character":"wolverine",
"picture":"618035022351.png"
}
in a single query using filters
{
"universe": "comics",
"saga.name": "x-men",
"saga.characters.character": "wolverine"
}
My MongoDB knowledge prevents me from correcting this.
Use the shell method findAndModify to suit your needs.
But you cannot use the positional character $ more than once while projecting in MongoDb, so you may have to keep track of it yourself at client-side.
Use arrayFilters to update deeply nested sub-document, instead of positional all operator $[].
Below is a working query -
var query = {
universe: 'comics'
};
var update = {
$set: {
'saga.$[outer].characters.$[inner].character': 'lobezno',
'saga.$[outer].characters.$[inner].picture': '618035022354.png',
}
};
var fields = {
'saga.characters': 1
};
var updateFilter = {
arrayFilters: [
{
'outer.name': 'x-men'
},
{
'inner.character': 'wolverine'
}
]
};
db.collection.findAndModify({
query,
update,
fields,
arrayFilters: updateFilter.arrayFilters
new: true
});
If I understand your question correctly, your updating is working as expected and your issue is that it returns the whole document and you don't want to query the database to just to return these two fields.
Why don't you just extract the fields from the document returned from your update? You are not going to the database when doing that.
var extractElementFromResult = null;
if(result != null) {
extractElementFromResult = result.saga
.filter(item => item.name == "x-men")[0]
.characters
.filter(item => item.character == "wolverine")[0];
}
Env:
MongoDB (3.2.0) with Mongoose
Collection:
users
Text Index creation:
BasicDBObject keys = new BasicDBObject();
keys.put("name","text");
BasicDBObject options = new BasicDBObject();
options.put("name", "userTextSearch");
options.put("unique", Boolean.FALSE);
options.put("background", Boolean.TRUE);
userCollection.createIndex(keys, options); // using MongoTemplate
Document:
{"name":"LEONEL"}
Queries:
db.users.find( { "$text" : { "$search" : "LEONEL" } } ) => FOUND
db.users.find( { "$text" : { "$search" : "leonel" } } ) => FOUND (search caseSensitive is false)
db.users.find( { "$text" : { "$search" : "LEONÉL" } } ) => FOUND (search with diacriticSensitive is false)
db.users.find( { "$text" : { "$search" : "LEONE" } } ) => FOUND (Partial search)
db.users.find( { "$text" : { "$search" : "LEO" } } ) => NOT FOUND (Partial search)
db.users.find( { "$text" : { "$search" : "L" } } ) => NOT FOUND (Partial search)
Any idea why I get 0 results using as query "LEO" or "L"?
Regex with Text Index Search is not allowed.
db.getCollection('users')
.find( { "$text" : { "$search" : "/LEO/i",
"$caseSensitive": false,
"$diacriticSensitive": false }} )
.count() // 0 results
db.getCollection('users')
.find( { "$text" : { "$search" : "LEO",
"$caseSensitive": false,
"$diacriticSensitive": false }} )
.count() // 0 results
MongoDB Documentation:
Text Search
$text
Text Indexes
Improve Text Indexes to support partial word match
As at MongoDB 3.4, the text search feature is designed to support case-insensitive searches on text content with language-specific rules for stopwords and stemming. Stemming rules for supported languages are based on standard algorithms which generally handle common verbs and nouns but are unaware of proper nouns.
There is no explicit support for partial or fuzzy matches, but terms that stem to a similar result may appear to be working as such. For example: "taste", "tastes", and tasteful" all stem to "tast". Try the Snowball Stemming Demo page to experiment with more words and stemming algorithms.
Your results that match are all variations on the same word "LEONEL", and vary only by case and diacritic. Unless "LEONEL" can be stemmed to something shorter by the rules of your selected language, these are the only type of variations that will match.
If you want to do efficient partial matches you'll need to take a different approach. For some helpful ideas see:
Efficient Techniques for Fuzzy and Partial matching in MongoDB by John Page
Efficient Partial Keyword Searches by James Tan
There is a relevant improvement request you can watch/upvote in the MongoDB issue tracker: SERVER-15090: Improve Text Indexes to support partial word match.
As Mongo currently does not supports partial search by default...
I created a simple static method.
import mongoose from 'mongoose'
const PostSchema = new mongoose.Schema({
title: { type: String, default: '', trim: true },
body: { type: String, default: '', trim: true },
});
PostSchema.index({ title: "text", body: "text",},
{ weights: { title: 5, body: 3, } })
PostSchema.statics = {
searchPartial: function(q, callback) {
return this.find({
$or: [
{ "title": new RegExp(q, "gi") },
{ "body": new RegExp(q, "gi") },
]
}, callback);
},
searchFull: function (q, callback) {
return this.find({
$text: { $search: q, $caseSensitive: false }
}, callback)
},
search: function(q, callback) {
this.searchFull(q, (err, data) => {
if (err) return callback(err, data);
if (!err && data.length) return callback(err, data);
if (!err && data.length === 0) return this.searchPartial(q, callback);
});
},
}
export default mongoose.models.Post || mongoose.model('Post', PostSchema)
How to use:
import Post from '../models/post'
Post.search('Firs', function(err, data) {
console.log(data);
})
Without creating index, we could simply use:
db.users.find({ name: /<full_or_partial_text>/i}) (case insensitive)
If you want to use all the benefits of MongoDB's full-text search AND want partial matches (maybe for auto-complete), the n-gram based approach mentioned by Shrikant Prabhu was the right solution for me. Obviously your mileage may vary, and this might not be practical when indexing huge documents.
In my case I mainly needed the partial matches to work for just the title field (and a few other short fields) of my documents.
I used an edge n-gram approach. What does that mean? In short, you turn a string like "Mississippi River" into a string like "Mis Miss Missi Missis Mississ Mississi Mississip Mississipp Mississippi Riv Rive River".
Inspired by this code by Liu Gen, I came up with this method:
function createEdgeNGrams(str) {
if (str && str.length > 3) {
const minGram = 3
const maxGram = str.length
return str.split(" ").reduce((ngrams, token) => {
if (token.length > minGram) {
for (let i = minGram; i <= maxGram && i <= token.length; ++i) {
ngrams = [...ngrams, token.substr(0, i)]
}
} else {
ngrams = [...ngrams, token]
}
return ngrams
}, []).join(" ")
}
return str
}
let res = createEdgeNGrams("Mississippi River")
console.log(res)
Now to make use of this in Mongo, I add a searchTitle field to my documents and set its value by converting the actual title field into edge n-grams with the above function. I also create a "text" index for the searchTitle field.
I then exclude the searchTitle field from my search results by using a projection:
db.collection('my-collection')
.find({ $text: { $search: mySearchTerm } }, { projection: { searchTitle: 0 } })
I wrapped #Ricardo Canelas' answer in a mongoose plugin here on npm
Two changes made:
- Uses promises
- Search on any field with type String
Here's the important source code:
// mongoose-partial-full-search
module.exports = exports = function addPartialFullSearch(schema, options) {
schema.statics = {
...schema.statics,
makePartialSearchQueries: function (q) {
if (!q) return {};
const $or = Object.entries(this.schema.paths).reduce((queries, [path, val]) => {
val.instance == "String" &&
queries.push({
[path]: new RegExp(q, "gi")
});
return queries;
}, []);
return { $or }
},
searchPartial: function (q, opts) {
return this.find(this.makePartialSearchQueries(q), opts);
},
searchFull: function (q, opts) {
return this.find({
$text: {
$search: q
}
}, opts);
},
search: function (q, opts) {
return this.searchFull(q, opts).then(data => {
return data.length ? data : this.searchPartial(q, opts);
});
}
}
}
exports.version = require('../package').version;
Usage
// PostSchema.js
import addPartialFullSearch from 'mongoose-partial-full-search';
PostSchema.plugin(addPartialFullSearch);
// some other file.js
import Post from '../wherever/models/post'
Post.search('Firs').then(data => console.log(data);)
If you are using a variable to store the string or value to be searched:
It will work with the Regex, as:
{ collection.find({ name of Mongodb field: new RegExp(variable_name, 'i') }
Here, the I is for the ignore-case option
The quick and dirty solution, that worked for me: use text search first, if nothing is found, then make another query with a regexp. In case you don't want to make two queries - $or works too, but requires all fields in query to be indexed.
Also, you'd better not to use case-insensitive rx, because it can't rely on indexes. In my case I've made lowercase copies of used fields.
Good n-gram based approach for fuzzy matching is explained here
(Also explains how to score higher for Results using prefix Matching)
https://medium.com/xeneta/fuzzy-search-with-mongodb-and-python-57103928ee5d
Note : n-gram based approaches can be storage extensive and mongodb collection size will increase.
I create an additional field which combines all the fields within a document that I want to search. Then I just use regex:
user = {
firstName: 'Bob',
lastName: 'Smith',
address: {
street: 'First Ave',
city: 'New York City',
}
notes: 'Bob knows Mary'
}
// add combined search field with '+' separator to preserve spaces
user.searchString = `${user.firstName}+${user.lastName}+${user.address.street}+${user.address.city}+${user.notes}`
db.users.find({searchString: {$regex: 'mar', $options: 'i'}})
// returns Bob because 'mar' matches his notes field
// TODO write a client-side function to highlight the matching fragments
full/partial search in MongodB for a "pure" Meteor-project
I adpated flash's code to use it with Meteor-Collections and simpleSchema but without mongoose (means: remove the use of .plugin()-method and schema.path (altough that looks to be a simpleSchema-attribute in flash's code, it did not resolve for me)) and returing the result array instead of a cursor.
Thought that this might help someone, so I share it.
export function partialFullTextSearch(meteorCollection, searchString) {
// builds an "or"-mongoDB-query for all fields with type "String" with a regEx as search parameter
const makePartialSearchQueries = () => {
if (!searchString) return {};
const $or = Object.entries(meteorCollection.simpleSchema().schema())
.reduce((queries, [name, def]) => {
def.type.definitions.some(t => t.type === String) &&
queries.push({[name]: new RegExp(searchString, "gi")});
return queries
}, []);
return {$or}
};
// returns a promise with result as array
const searchPartial = () => meteorCollection.rawCollection()
.find(makePartialSearchQueries(searchString)).toArray();
// returns a promise with result as array
const searchFull = () => meteorCollection.rawCollection()
.find({$text: {$search: searchString}}).toArray();
return searchFull().then(result => {
if (result.length === 0) throw null
else return result
}).catch(() => searchPartial());
}
This returns a Promise, so call it like this (i.e. as a return of a async Meteor-Method searchContact on serverside).
It implies that you attached a simpleSchema to your collection before calling this method.
return partialFullTextSearch(Contacts, searchString).then(result => result);
import re
db.collection.find({"$or": [{"your field name": re.compile(text, re.IGNORECASE)},{"your field name": re.compile(text, re.IGNORECASE)}]})
This query works perfectly
{
$or:[{author:this.userId} , {somethingelse:true} ]
}
But when I try:
{
$or:[{author:this.userId} , {sharedwith[this.userId]:true} ]
}
I receive the message
Errors prevented startup:
While processing files with ecmascript (for target os.linux.x86_64): server/main.js:113:43: Unexpected token, expected
, (113:43)
=> Your application has errors. Waiting for file change.
And thats where the comma , in the $or statement is
Help
I guess that you are trying to retrieve all documents for which the current user is the author, or which have been shared with him/her? And therefore that you have structured your documents with a sharedWith field which is a hash map of userId as keys and boolean as value?
Document structure:
{
author: string,
sharedWith: {
<userId1>: boolean
// <userId2>…
}
}
In that case, your MongoDB query should use the dot notation to specify the value of a nested field within sharedWith field:
{
$or: [{
author: string
}, {
"sharedWith.<userId>": boolean
}]
}
To easily create the query with the interpolated value of <userId>, you can use a computed key in your object (ES6 syntax):
{
$or:[{
author: this.userId
} , {
// The query computed key must be in square brackets.
// Specify the field child key using the dot notation within your query.
["sharedwith." + this.userId]: true
}]
}
Or with good old ES5 syntax, similarly to #MichelFloyd's answer:
var query = {
$or: [{
author: this.userId
}]
};
var newCondition = {};
newCondition["sharedWith." + this.userId] = true;
query.$or.push(newCondition);
Note: the above described document structure could conveniently replace the sharedWith hash map by an array (since having a false value for the boolean could simply be replaced by removing the corresponding userId from the array):
{
author: string,
sharedWith: [
<userId1>
// <userId2>…
]
}
In which case the query would simply become:
{
$or:[{
author: this.userId
} , {
// In MongoDB query, the below selector matches either:
// - documents where `sharedWith` value is a string equal to
// the value of `this.userId`, or
// - documents where `sharedWith` value is an array which contains
// an element with the same value as `this.userId`.
sharedwith: this.userId
}]
}
Try building the query as a variable before running it.
let query = { $or: [{ author: this.userId }]};
const sw = sharedwith[this.userId];
query.$or.push({sw: true});
MyCollection.find(query);
I'm trying to update a sub document on an existing collection. I'm getting a MongoDB error message.
"MongoError: The positional operator did not find the match needed from the query. Unexpanded update: articleWords.$ [409]"
From my Articles Simple Schema
"articleWords.$": {
type: Object
},
"articleWords.$.wordId": {
type: String,
label: 'Word ID'
},
"articleWords.$.word": {
type: String,
label: 'Word'
},
Update Function
function updateArticle(_id,wordArr) {
_.each(wordArr,function(elem) {
var ret = Articles.update(
{'_id': _id},
{ $set: { 'articleWords.$': { 'wordId': elem.wordId, 'word': elem.word } }
});
});
return true;
}
As you can see I am passing an array of objects. Is there a better way to do this than _.each ?
CLARIFICATION
Thank you to #corvid for the answer. I think I didn't make my question clear enough. There does exist an article record, but there is no data added to the articleWords attribute. Essentially we are updating a record but insert into the articleWords array.
A second attempt, is also not working
_.each(wordArr,function(elem) {
var ret = Articles.update(
{'_id': _id},
{ $set: { 'articleWords.$.wordId': elem.wordId, 'articleWords.$.word': elem.word } }
);
});
Yes, you need your selector to match something within the subdocument. For example,
Articles.update({
'_id': <someid>,
'words.wordId': <somewordid>
}, {
$set: {
'words.$.word': elem.word,
'words.$.wordId': elem.wordId
}
});
If the array doesn't exist yet then you're going about this in the hardest way possible. You can just set the entire array at one go:
var ret = Articles.update(
{'_id': _id},
{ $set: { articleWords: wordArr }}
);
I can see that wordArr already has the id and string. This will work as long as it doesn't have more content. If it does then you can just make a second version with the parts you want to keep.