I have an array that have this format:
data{
[sequentialId]{guid:value1,name:value2}
}
I need to do something like db.data.find("data.?.name":"value1")
All the solutions I've seen don't work because they are expecting me to know the name of the attribute, but in this case the ID is sequential.
I've looked at the standard way of querying nested documents described here
https://docs.mongodb.com/manual/tutorial/query-array-of-documents/
I also looked at some options like $unwind but I can't get anything to work
here's a small sample
{"41":{"b":453081600,"f":1,"h":171,"s":4,"w":4,"wr":[2,0]},
"80":{"b":337132800,"f":2,"h":169,"s":4,"w":4,"wr":[0,0]},
"388":{"b":148694400,"f":1,"h":188,"l":{"c":[{"e":2001,"g":13,"m":292,"s":1992,"t":18},{"e":2006,"g":11,"m":197,"s":2001,"t":1},{"e":2009,"g":2,"m":111,"s":2006,"t":1790},{"e":2009,"g":0,"m":1,"s":2009,"t":1937},{"e":2010,"g":1,"m":14,"s":2010,"t":1},{"e":2011,"g":0,"m":8,"s":2010,"t":13}],"n":[{"e":2007,"g":1,"m":73,"s":1996,"t":1318}]},"s":2,"w":3,"wr":[0,0]}}
for example in this set of data I might need to query all the docs where "f"=1
The following query can get us the expected output:
Note: We are fetching the documents which have name is equal to a
db.collection.aggregate([
{
$addFields:{
"filtered":{
$filter:{
"input":"$data",
"as":"info",
"cond":{
$let:{
"vars":{
"array":{
$objectToArray:"$$info"
}
},
"in":{
$in:["a","$$array.v.name"]
}
}
}
}
}
}
},
{
$match:{
"filtered.0":{
$exists:true
}
}
},
{
$project:{
"filtered":0
}
}
]).pretty()
Data set:
{
"data":[
{
"41": {
"b": 453081600,
"name": "a"
},
"80": {
"b": 337132800,
"name": "b"
},
"388": {
"b": 148694400,
"name": "c"
}
}
]
}
{
"data":[
{
"41": {
"b": 453081600,
"name": "b"
},
"80": {
"b": 337132800,
"name": "b"
},
"388": {
"b": 148694400,
"name": "c"
}
}
]
}
Output:
{
"data":[
{
"41": {
"b": 453081600,
"name": "a"
},
"80": {
"b": 337132800,
"name": "b"
},
"388": {
"b": 148694400,
"name": "c"
}
}
]
}
Query analysis:
We are creating a filtered array to hold only those records from data array which contains name equal to a inside any subdocument with an unknown key.
It's done by first converting each document of data into an array of key-value pairs. Now we can directly query the values without worrying about the keys.
Finally, filter those documents in which the size of filtered array is greater than zero.
Related
I'm forced to use the aggregation framework and the project operation of Spring Data MongoDb.
What I'd like to do is creating an array of object as a result of a project operation.
For example, considering this intermediate aggregation result:
[
{
"content": {
"processes": [
{
"id": "101a",
"title": "delivery"
},
{
"id": "101b",
"title": "feedback"
}
]
}
}
]
What I want to obtain is this:
[
{
"results":
{
"titles": [
{
"id": "101a",
"value": "delivery"
},
{
"id": "101b",
"value": "feedback"
}
]
}
}
]
This was just an example, I don't want to simply "rename" some fields.
What I want is the possibility to create an array of objects.
If I try something like this:
projectionOperation
.and("$content.processes.id").as("results.titles.id")
.and("$content.processes.title").as("results.titles.value");
I obtain this:
[
{
"results":
{
"titles": {
"id": ["101a", "101b"]
"value": ["delivery", "feedback"]
}
}
}
}
]
With this projection the array is created, but not "in the proper position".
However, If I use the nested operator, I haven't figure out a way to specify that I want to create an array instead of an object.
With this projection:
projectionOperation.and("results.titles")
.nested(
bind("id", "process.id")
.and("value", "process.title")
);
I can create a proper nested object but not into an array:
"results.titles": {
"id": "101b",
"value": "feedback"
}
You can try below aggregation code.
ProjectionOperation po = Aggregation.project().and(
VariableOperators.mapItemsOf("content.processes").as("rt")
.andApply(
new AggregationExpression() {
#Override
public Document toDocument(AggregationOperationContext aggregationOperationContext) {
return new Document("id", "$$rt.id").append("value", "$$rt.title");
}
}
)
).as("result");
I've a problem with a huge MongoDb aggregation pipeline. I've many constraint and I've simplified the problem a lot. Hence, don't discuss the goal for this query.
I've a mongo aggregation that gives something similar to this:
[
{
"content": {
"processes": [
{
"id": "101a",
"title": "delivery"
},
{
"id": "101b",
"title": "feedback"
}
]
}
}
]
To this intermediate result I'm forced to apply a project operation in order to obtain something similar to this:
[
{
"results":
{
"titles": [
{
"id": "101a",
"value": "delivery"
},
{
"id": "101b",
"value": "feedback"
}
]
}
}
]
enter code here
But applying this projections:
"results.titles.id": "$content.processes.id",
"results.titles.value": "$content.processes.title"
I obtain this:
[
{
"results":
{
"titles": {
"id": ["101a", "101b"]
"value": ["delivery", "feedback"]
}
}
}
}
]
Collection are created but not in the proper position.
Is it possible to exploit some operator inside the project operation in order to tell mongo to create an array in a parent position?
Something like this:
"results.titles.$[x].value" : "$content.processes.value"
You can use the dot notation to project entire array:
db.col.aggregate([
{
$project: {
"results.titles": "$content.processes"
}
}
])
and if you need to rename title to value then you have to apply $map operator:
db.col.aggregate([
{
$project: {
"results.titles": {
$map: {
input: "$content.processes",
as: "process",
in: {
id: "$$process.id",
value: "$$process.title"
}
}
}
}
}
])
I have a collection with documents similar to such:
{
"_id": ObjectId("xxxxx"),
"item": [
{ "property": ["attr1", "+1"] },
{ "property": ["attr2", "-1"] }
]
}
{
"_id": ObjectId("xxxxy"),
"item": [
{ "property": ["attr1", "-1"] },
{ "property": ["attr2", "0"] }
]
}
{
"_id": ObjectId("xxxxz"),
"item": [
{ "property": ["attr1", "0"] },
{ "property": ["attr2", "+1"] }
]
}
Preferably using an aggregation pipeline, is there any way to match the document if and only if any one of the properties match more than one condition?
For example, I want a query where one object in the array matches both of these conditions:
("item.property": "attr1") AND ("item.property": /^\+/)
That is, a single property where it contains "attr1" and an element that starts with "+".
However, using my current query that looks like this:
collection.aggregate(
{ $match:
{ $and:
[
{ "item.property": "attr1" },
{ "item.property": /^\+/ }
]
}
}
This would match both the first and last document because both contain a property with "attr1" and an element that stats with "+". However, I do not want this query to match the last document, since the element that starts with "+" does not belong to the same object in the array.
Is there any way to achieve this behavior using the aggregation framework?
You can use the below query with $elemMatch to match the array's both values.
Something like
db.collection_name.aggregate({
"$match": {
"item": {
"$elemMatch": {
"property.0": "attr1",
"property.1": /^\+/
}
}
}
});
Also, you can use $all operator if you don't want to reference array index.
db.collection_name.aggregate({
"$match": {
"item": {
"$elemMatch": {
"property": {
"$all": [
"attr1",
/^\+/
]
}
}
}
}
});
I have a collection like this:
{
"_id": {
"$oid": "53f34ef8ec10d6fa97dcc34b"
},
"editions": [
{
"number": 1,
...
},
{
"number": 2,
...
},
...
]
}
I want filter results of my query by some number.
I tried
criterias.add(query.criteria("editions.number").equal(paramNumber));
And
query.filter("editions.number =", paramNumber)
However I just received all collection, when I pass paramNumber equals 2. What I want is receive the following result:
{
"_id": {
"$oid": "53f34ef8ec10d6fa97dcc34b"
},
"editions": [
{
"number": 2,
...
}
]
}
What am I doing wrong?
You can't receive partial arrays like that. You'll get back with the full document/object or just the fields you've specified in a projection.
I have the following records:
Record 1:
{
"status": "active",
"users": [
{
"name": "foo",
"status": "a"
},
{
"name": "foo",
"status": "b"
}
]
}
Record 2:
{
"status": "active",
"users": [
{
"name": "bar",
"status": "a"
},
{
"name": "foo",
"status": "b"
}
]
}
Now, I wish to return only those records in which the user.name is "foo" and the user.status is "a" - That is I need to get Record 1 back since it satisfies my requirements.
How do I do the AND operation on the array within the record to achieve this?
I tried the following query:
{
"$and": [
{
"users.name": "foo"
},
{
"users.status": "a"
}
]
}
but I get both the records - I need only the first record (since in the users array, it has an entry where the name is "foo" AND the status is "a").
Any clues?
Ok, I found the answer out here
The solution would be to have a query as follows:
{
"users": {
"$elemMatch": {
"name": "foo",
"status": "a"
}
}
}
That did the trick!
Instead of individual field values you can also use whole objects in find queries. Try:
db.collection.find( {
users: {
"name":"foo",
"status":"a"
}
});
This should return all documents where the users array includes an object (or is an object) which looks as described. But note that this doesn't work when the object has additional fields.