Currently, that's my current document:
{
_id: 'd283015f-91e9-4404-9202-093c28d6a931',
referencedGeneralPractitioner: [
{
resourceType: 'practitioner',
cachedIdentifier: [
{
system: { value: 'urn:oid:1.3.6.1.4.1.19126.3' },
value: { value: '14277399B' }
}
]
}
]
}
Here, there's two nested objects arrays: referencedGeneralPractitioner[{cachedIdentifier[{}]}].
Currently, I'm getting results using this query:
{
"referencedGeneralPractitioner":{
"$elemMatch":{
"cachedIdentifier.value.value":"14277399B",
"cachedIdentifier.system.value":"urn:oid:1.3.6.1.4.1.19126.3"
}
}
}
It's getting my desired document, but I don't quite figure out if above query is which I'm really looking for.
I mean, I'm only applying $elemMatch on referencedGeneralPractitioner field array.
Is it really enought?
Should I add a nested $elemMatch on cachedIdentifier?
Any ideas?
It looks like you need to query it like this:
db.collection.find({
"referencedGeneralPractitioner.cachedIdentifier": {
"$elemMatch": {
"value.value": "14277399B",
"system.value": "urn:oid:1.3.6.1.4.1.19126.3"
}
}
})
playground
This is in case you need to find the full document having $and of both values in same element in any of the elements in the nested array , if you need to extract specific element you will need to $filter
if you need to search also based on element in the 1st array level then you need to modify as follow:
{
"referencedGeneralPractitioner": {
"$elemMatch": {
resourceType: 'practitioner',
"cachedIdentifier": {
"$elemMatch": {
"value.value": 1,
"system.value":2
}
}
}
}
}
This will give you all full documents where at same time there is resouceType:"practitioner" and { value.value:3 and system.value: 2 }
Also is important to stress that this will not gona work correctly!:
{
"referencedGeneralPractitioner":{
"$elemMatch":{
"cachedIdentifier.value.value":"14277399B",
"cachedIdentifier.system.value":"urn:oid:1.3.6.1.4.1.19126.3"
}
}
}
Since it will match false positives based on any single value in the nested elements like:
wrong playground
Related
there is a nested mongodb document that looks like the image below. I want to do a search in the body field in this document, but I could not succeed. how can i do this search. thanks in advance
I tried to search like this. Is my path correct?
const result = await this.campaignModel.find({
"sequencesPageData": {
"$elemMatch": {
"mailSteps": {
"$elemMatch": {
"mailTemplate": x
}
}
}
}
});
I did a search like this but got no results.
const result = await this.campaignModel.find({
"sequencesPageData": {
"$elemMatch": {
"mailSteps": {
"$elemMatch": {
"mailTemplate": x
}
}
}
}
});
For object fields, simply access them using dot notation. For array fields, use $elemMatch to perform the match.
db.collection.find({
"sequencesPageData.mailSteps": {
"$elemMatch": {
"mailTemplate": {
"$elemMatch": {
"subject": "asdf"
}
}
}
}
})
Mongo Playground
If you are only testing a single field in the array, there is no need to use $elemMatch, you can use dot notation:
db.collection.find({ "sequencesPageData.mailSteps.mailTemplate.body": "x" })
$elemMatch is useful to ensure that 2 or more tests are satisfied by the same array element, but since this example uses only 1 test, it works without.
i have a document structured this way
{
_id:'1'
text:'xxxxxxxc'
choices:{
a:['xxx','yyy','zzz'],
b:['aaa','bbb','ccc'],
c:['lll','mmm','ddd'],
}
}
....and many other document...
{
_id:'2'
text:'xxxxxxxc'
choices:{
a:['ooo','sss','qqq'],
b:['iii','hhh','ggg'],
c:['ddd','eee','fff'],
}
}
so i cant figure out to search if any of choices key contains an array that contains some string
to be more precise: i want to query entire document and return the document if ANY of the choices keys' array has element that matches the query.
so if i search for 'yyy' , it should simply return document of_id:1 and other docs, that has 'yyy' in array in any of its choices key
(be it in a,b,c, these keys can be more than c, that is to z and beyond)
...and not the _id:2 because it has no element 'yyy' in any of its array of its choice
db.collection.aggregate([
{
$addFields: {
"c": {
"$objectToArray": "$choices"
}
}
},
{
$match: {
"c.v": "yyy"
}
},
{
"$project": {
c: 0
}
}
])
Reshape and find what you need. Ignore other temp fields created.
Playground
I have a document which looks like this
{
_id:1,
list_id:23,
name:'list01'
cards:[
{
id:3,
name:'card01'
categories:[{
id:10,
category:'section01',
tags:[{id:11,name:'tag01',is_selected: true}]
}]
}
]
}
I need to insert/push some data to tags array in a selected category for a given list_id but I'm getting an error saying
MongoError: Too many positional (i.e. '$') elements found in path
'cards.$.categories.$.tags'
This is the query that I have tried out. What's wrong with this query any idea on how to achieve this?
db.collection(TABLE)
.updateOne(
{ list_id: 23, 'cards.categories.category': 'section01'},
{ $push: { 'cards.$.categories.$.tags': { name: 'tag02', id: uuidv4(), is_selected: true } } }
);
You can not use multiple $ positional, for your case you can use single positional and arrayFilters,
The filtered positional operator $[<identifier>] identifies the array elements that match the arrayFilters conditions for an update operation,
db.collection(TABLE).updateOne({
list_id: 23,
"cards.categories.category": "section01"
},
{
$push: {
"cards.$.categories.$[elem].tags": {
name: "tag02",
id: uuidv4(),
is_selected: true
}
}
},
{
arrayFilters: [
{ "elem.category": "section01" }
]
})
Playground
In short, it is not possible.
Nested Arrays
The positional $ operator cannot be used for queries which traverse
more than one array, such as queries that traverse arrays nested
within other arrays, because the replacement for the $ placeholder is
a single value
https://docs.mongodb.com/manual/reference/operator/update/positional/
However, you may want to try $[]
Nested Arrays The filtered positional operator $[] can be
used for queries which traverse more than one array and nested arrays.
For an example, see Update Nested Arrays in Conjunction with $[].
https://docs.mongodb.com/manual/reference/operator/update/positional-filtered/#position-nested-arrays-filtered
You can use $[identifier]
db.collection.update({
"list_id": 23,
"cards.categories.category": "section01"
},
{
$push: {
"cards.$.categories.$[elem].tags": {
name: "tag02",
id: uuidv4(),
is_selected: true
}
}
},
{
arrayFilters: [
{
"elem.category": "section01"
}
],
multi: true
})
try it here
I am facing an issue in deleting an array from db.
I want to delete the [2] array with its id as condition.
I have tried many things, but none give results as expected.
db.users.update({ '_id': ObjectId("53689fa45bac9757f81fbb77")},{ '$pull' : { 'injury._id': ObjectId("5379974ac76d005c2d00005c") } })
Use the $pull operator to remove the element you do not want:
db.collection.update(
{ "injury._id": ObjectId("53760d9820b6ee683000005c") },
{
"$pull": {
"injury": { "_id": ObjectId("53760d9820b6ee683000005c") }
}
}
)
Forgive me if the actual _id values do not match as you posted a screenshot.
I guess, something like this should work
.update(..., { $pull: { injury: {_id: YOUR_ID } } })
The format of $pull is
$pull: { arrayName: { array item query } }
You can use unset() if you're using PHP
I have a collection of documents in the following form:
{ _id: ObjectId(...)
, title: "foo"
, tags: ["bar", "baz", "qux"]
}
The query should find all documents with any of these tags. I currently use this query:
{ "tags": { "$in": ["bar", "hello"] } }
And it works; all documents tagged "bar" or "hello" are returned.
However, I want to sort by relevance, i.e. the more matching tags the earlier the document should occur in the result. For example, a document tagged ["bar", "hello", "baz"] should be higher in the results than a document tagged ["bar", "baz", "boo"] for the query ["bar", "hello"]. How can I achieve this?
MapReduce and doing it client-side is going to be too slow - you should use the aggregation framework (new in MongoDB 2.2).
It might look something like this:
db.collection.aggregate([
{ $match : { "tags": { "$in": ["bar", "hello"] } } },
{ $unwind : "$tags" },
{ $match : { "tags": { "$in": ["bar", "hello"] } } },
{ $group : { _id: "$title", numRelTags: { $sum:1 } } },
{ $sort : { numRelTags : -1 } }
// optionally
, { $limit : 10 }
])
Note the first and third pipeline members look identical, this is intentional and needed. Here is what the steps do:
pass on only documents which have tag "bar" or "hello" in them.
unwind the tags array (meaning split into one document per tags element
pass on only tags exactly "bar" or "hello" (i.e. discard the rest of the tags)
group by title (it could be also by "$_id" or any other combination of original document
adding up how many tags (of "bar" and "hello") it had
sort in descending order by number of relevant tags
(optionally) limit the returned set to top 10.
You could potentially use MapReduce for something like that. You'd process each document in the Map step, figuring out how many tags match the query, and assign a score. Then you could sort based on that score.
http://www.mongodb.org/display/DOCS/MapReduce
Something that complex should be done after querying. Either server-side through db.eval (if your client supports this) or just clientside. Here's an example for what you're looking for.
It will retreive all posts with the tags you specified, then sorts them according to the amount of matches.
remove the db.eva( part and translate it to the language your client uses to query to get the clientside effect (
db.eval(function () {
var tags = ["a","b","c"];
return db.posts.find({tags:{$in:tags}}).toArray().sort(function(a,b){
var matches_a = 0;
var matches_b = 0;
a.tags.forEach(function (tag) {
for (t in tags) {
if (tag == t) {
matches_a++;
} else {
matches_b++;
}
}
});
b.tags.forEach(function(tag) {
for (t in tags) {
if (tag == t) {
matches_b++;
} else {
matches_a++;
}
}
});
return matches_a - matches_b;
});
});