I have data for jsonlogic rule:
{ "component": { "tableNumber": 102}, "refcomponents": [ { "tableNumber": 102}, {"tableNumber": 302} ] }
and i need to check if component's tableNumber is found in refcomponents array. Can this be done? If not what would be a workaround?
Following rule does not work because var is relative to items in refcomponent-array:
{ "some" : [ { "var": "refcomponents" }, { "==" : [{ "var": "component.tableNumber"} , { "var" : "tableNumber" }]}]}
so component.tableNumber is null and is never evaluated true.
Thanks!
Related
I have some documents like this:
doc = {
"tag" : "tag1",
"field" : {
"zone" :"zone1",
"arr" : [
{ vals: [-12.3,-1,0], timestamp: ""},
{ vals: [-30.40,-23.2,0], timestamp: "" }
]
}
}
I want to modify one of the elements of the array (for example, the first element, the one with index 0) of one of such documents.
I want to end it up looking like:
doc = {
"tag" : "tag1",
"field" : {
"zone" :"zone1",
"arr" : [
{ vals: [-1, -1, -1], timestamp: "the_new_timestamp"}, // this one was modified
{ vals: [-30.40, -23.2, 0], timestamp: "" }
]
}
}
I know something about find_and_modify:
db.mycollection.find_and_modify(
query = query, // you find the document of interest with this
fields = { }, // you can focus on one of the fields of your document with this
update = { "$set": data }, // you update your data with this
)
The questions that feel closer to what I want are these:
https://stackoverflow.com/a/28829203/1253729
https://stackoverflow.com/a/23554454/1253729
I've been going through them but I'm getting stuck when trying to work out the solution for my case. I don't know if I should really use the fields parameter. I don't know how to use $set correctly for my case.
I hope you could help me.
https://docs.mongodb.com/manual/reference/operator/update/positional/
This will help you!
db.mycollection.updateOne(
query,
fields,
{ $set: { "field.arr.0.timestamp": "the_new_timestamp"} }
)
I have a document like this:
{
"_id" : "4mDYgt6gID",
...
"MultipleChoiceQuestions" : [
{
...
"LeadInFile" : null,
...
},
{
...
"LeadInFile" : 'some string',
...
}
],
...
}
How do I query for any documents that have a non-null value in LeadInFile?
I'm trying different things, currently something like this
db.getCollection('QuizTime:Quizzes').find({"MultipleChoiceQuestions": [{ "LeadInFile": { $ne: null}}]});
Is returning 0 records.
The current form of the query is saying:
Find documents where MultipleChoiceQuestions is [{ "LeadInFile": { $ne: null}}]
Try using dot notation; this is used to access elements of an array or fields in an embedded document. For example:
db.getCollection('QuizTime:Quizzes').find({
"MultipleChoiceQuestions.LeadinFile" : { "$ne" : null }
})
I have a tricky mongoDB problem that I have never encountered.
The Documents:
The documents in my collection have a search object containing named keys and array values. The keys are named after one of eight categorys and the corresponding value is an array containing items from that category.
{
_id: "bRtjhGNQ3eNqTiKWa",
/* */
search :{
usage: ["accounting"],
test: ["knowledgetest", "feedback"]
},
test: {
type:"list",
vals: [
{name:'knowledgetest', showName: 'Wissenstest'},
{name:'feedback', showName: '360 Feedback'},
]
},
usage: {
type:"list",
vals: [
{name:'accounting', showName: 'Accounting'},
]
}
},
{
_id: "7bgvegeKZNXkKzuXs",
/* */
search :{
usage: ["recruiting"],
test: ["intelligence", "feedback"]
},
test: {
type:"list",
vals: [
{name:'intelligence', showName: 'Intelligenztest'},
{name:'feedback', showName: '360 Feedback'},
]
},
usage: {
type:"list",
vals: [
{name:'recruiting', showName: 'Recruiting'},
]
}
},
The Query
The query is an object containing the same category - keys and array - values.
{
usage: ["accounting", "assessment"],
test : ["feedback"]
}
The desired outcome
If the query is empty, I want all documents.
If the query has one category and any number of items, I want all the documents that have all of the items in the specified category.
If the query has more then one category, I want all the documents that have all of the items in all of the specified categorys.
My tries
I tried all kinds of variations of:
XX.find({
'search': {
"$elemMatch": {
'tool': {
"$in" : ['feedback']
}
}
}
No success.
EDIT
Tried: 'search.test': {$all: (query.test ? query.test : [])} which gives me no results if I have nothing selected; the right documents when I am only looking inside the test category; and nothing when I additionally look inside the usage category.
This is at the heart of my app, thus I historically put up a bounty.
let tools = []
const search = {}
for (var q in query) {
if (query.hasOwnProperty(q)) {
if (query[q]) {
search['search.'+q] = {$all: query[q] }
}
}
}
if (Object.keys(query).length > 0) {
tools = ToolsCollection.find(search).fetch()
} else {
tools = ToolsCollection.find({}).fetch()
}
Works like a charm
What I already hinted at in the comment: your document structure does not support efficient and simple searching. I can only guess the reason, but I suspect that you stick to some relational ideas like "schemas" or "normalization" which just don't make sense for a document database.
Without digging deeper into the problem of modeling, I could imagine something like this for your case:
{
_id: "bRtjhGNQ3eNqTiKWa",
/* */
search :{
usage: ["accounting"],
test: ["knowledgetest", "feedback"]
},
test: {
"knowledgetest" : {
"showName": "Wissenstest"
},
"feedback" : {
"showName": "360 Feedback"
}
},
usage: {
"accounting" : {
"values" : [ "knowledgetest", "feedback" ],
"showName" : "Accounting"
}
}
},
{
_id: "7bgvegeKZNXkKzuXs",
/* */
search : {
usage: ["recruiting"],
test: ["intelligence", "feedback"]
},
test: {
"intelligence" : {
showName: 'Intelligenztest'
},
"feedback" : {
showName: '360 Feedback'
}
},
usage: {
"recruiting" : {
"values" : [ "intelligence", "feedback" ],
"showName" : "Recruiting"
}
}
}
Then, a search for "knowledgetest" and "feedback" in "accounting" would be a simple
{ "usage.accounting.values" : { $all : [ "knowledgetest", "feedback"] } }
which can easily be used multiple times in an and condition:
{
{ "usage.accounting.values" : { $all : [ "knowledgetest", "feedback"] } },
{ "usage.anothercategory.values" : { $all [ "knowledgetest", "assessment" ] } }
}
Even the zero-times-case matches your search requirements, because an and-filter with none of these criteria yields {} which is the find-everything filter expression.
Once more, to make it absolutely clear: when using mongo, forget everything you know as "best practice" from the relational world. What you need to consider is: what are your queries, and how can my document model support these queries in an ideal way.
I have a user model like this:
user : {
myArmy : {
mySoldiers : [
{
positioned : false,
soldierInfo : {
_id : s99212
}
},
{
positioned : true,
soldierInfo : {
_id : s99112
}
}
]
}
},
user : {
myArmy : {
mySoldiers : [
{
positioned : true,
soldierInfo : {
_id : s99212
}
},
{
positioned : false,
soldierInfo : {
_id : s99112
}
}
]
}
}
...
I have a query that i want to do to return the user(s) who have soldier id s99212 positioned (true): (could be thousands of those, and i need to read and retrieve them all)
This is my faulty query with mongoose:
var soldierId = s99212;
stream = User.find({
$and: [
{'myArmy.mySoldier.positioned': {$ne: null}},
{'myArmy.mySoldier.soldierInfo._id': soldierId}
]
}).lean(true).stream();
Nothing is returned by this query, should there be another way to do this $and stuff?
How exactly am i suppose to use $elemMatch if at all, should it be instead of the find? (If it worth to mention, i want to return the complete user object, not just parts of it...)
Tried this, crashed my app:
stream = User.find({
'$elemMatch': [
{'myArmy.mySoldiers.pos': {$ne: null}},
{'myArmy.mySoldiers.soldierInfo._id': soldierId}
]
}).lean(true).stream();
I know i have a small syntax problem, where is it?
Very simple and well documented. The $elemMatch operator acts as a "query in itself", where it applies "it's conditions" to members of the array specified:
var query = User.find({
"myArmy.mySoldiers": {
"$elemMatch": {
"positioned": { "$ne": null },
"soldierInfo._id": soldierId
}
}
});
Therefore for a document to "match" then the conditions specfied under $elemMatch must be present and valid for the "same" array element. Array on "left", arguments on "right".
Other "dot notation" forms only ever test that the values match "some element" in the array, and not necessarily the same one.
I have a collection containing documents. Each document has a part attribute containing an Array of Hash (documents). These documents may or may not have a _encwas attribute.
{
_id : "00001",
parts : [
{ _encwas: 1, body: "" },
{ body: "" }
]
},
{
_id : "00002",
parts : [
{ _encwas: 1, body: "" },
{ _encwas: 2, body: "" }
]
},
{
_id : "00003",
parts : [
{ body: "" },
{ body: "" }
]
}
Is there a quick way to find all records where at least one part contains a _encwas attribute?
The following query works
db.collection.find({ "parts.0._encwas" : { $exists : true } });
but I would love to find a way to replace 0 with any part. For example
db.collection.find({ "parts.*._encwas" : { $exists : true } });
The query should be as efficient as possible (I don't mind if I need to create additional indexes) because I need to iterate more than 1M records.
This seemed to work when I tried with your test data:
db.collection.find( { "parts._encwas": { $exists : true } } )
Moreover, you can find all documents containing _encwas having a specific value using:
db.collection.find( { "parts._encwas": 4 } )
...where 4 is the value...
I believe the relevant part of the documentation is here: Dot Notation