Suppose the collection is like this:
db.mytests.find()
{ "_id" : ObjectId("4fb277b89b8295a790efde44"),
"mylist": [
{ "foo1" :"bar1", "foo2" : "bar2" },
{"foo1" : "bar3", "foo2" : "bar4" }
],
"nonlist" : "nonlistVal" }
I want to remove a document in mylist whose foo1 equal to bar1, after reading mongodb document about updating I used this:
db.mytests.update({},{$pull:{'mylist':{'mylist.$.foo1':'bar1'}}})
but it failed.
To figure out the problem I insert a new array into mytests using this:
db.mytests.update({},{$set:{'anotherList':[1,2,3,4]}})
and then using db.mytests.update({},{$pull:{'anotherList':{$gt:3}}}) to pull the element
4 in array anotherList ,it succeed.
I supposed the problem is with the mylist.$.foo1 ? Can you tell me the right way to remove a document element in a array?
Try changing:
db.mytests.update({},{$pull:{'mylist':{'mylist.$.foo1':'bar1'}}})
to:
db.mytests.update({},{$pull:{'mylist':{'foo1':'bar1'}}})
Related
I have lots of documents inside a collection.
The structure of each of the documents inside the collection is as it follows:
{
"_id" : ObjectId(....),
"valor" : {
"AB" : {
"X" : 0.0,
"Y" : 142.6,
},
"FJ" : {
"X" : 0.2,
"Y" : 3.33
....
The collection has currently about 200 documents and I have noticed that one of the keys inside valor has the wrong name. In this case we will say "FJ" shall be "JOF" in all the docs of the collection.
Im pretty sure it is possible to change the key in all the docs using the update function of pymongo. The problem I am facing is that when I visit the online doc available https://docs.mongodb.com/v3.0/reference/method/db.collection.update/ only explains how to change the values(which I would like to remain how they currently are and change only the keys).
This is what I have tried:
def multi_update(spec_key,key_updte):
rdo=col.update((valor.spec_key),{"$set":(valor.key_updte)},multi=True)
return rdo
print(multi_update('FJ','JOF'))
But outputs name 'valor' is not defined . I thought I shall use valor.specific_key to access to the corresponding json
how can I update a key only along the docs of the collection?
You have two problems. First, valor is not an identifier in your Python code, it's a field name of a MongoDB document. You need to quote it in single or double quotes in Python in order to make it a string and use it in a PyMongo update expression.
Your second problem is, MongoDB's update command doesn't allow you set one field to the value of another, nor to rename a field. However, you can reshape all the documents in your collection using the aggregate command with a $project stage and store the results in a second collection using a $out stage.
Here's a complete example to play with:
db = MongoClient().test
collection = db.collection
collection.delete_many({})
collection.insert_one({
"valor" : {
"AB" : {
"X" : 0.0,
"Y" : 142.6,
},
"FJ" : {
"X" : 0.2,
"Y" : 3.33}}})
collection.aggregate([{
"$project": {
"valor": {
"AB": "$valor.AB",
"FOJ": "$valor.FJ"
}
}
}, {
"$out": "collection2"
}])
This is the dangerous part. First, check that "collection2" has all the documents you want, in the desired shape. Then:
collection.drop()
db.collection2.rename("collection")
import pprint
pprint.pprint(collection.find_one())
I have a collection like this in my mongo database, let's say it's called taxonomic.
{
"_id" : ObjectId("5810e15a762a39b41912a131"),
"validName" : "Eros",
"idUser" : ObjectId("1")
}
{
"_id" : ObjectId("5810e15a762a39b41912a132"),
"validName" : "Eros",
"idUser" : ObjectId("2")
}
I've already created a compound index to be able to search for the two values I want, such as this.
db.taxonomic.createIndex({"idUser":1,"validName":1})
Now, I want to be able to search and get a return from it only when both of the parameters are found on the same document of the collections, here's my try:
db.taxonomic.find({$text:{$search:"Eros 2"}},{idUser:1,validName:1})
The problem with this method is that it will return any match of "Eros" OR "2", what I want is a return of the values when "Eros" AND "2" are matched in a document of the collection.
Thank you for any help!
I dont think you require a text Index for it if you only want specific string
db.taxonomic.find({"$or" : [{"validName" : "Eros"},{"validName" : "2"}]},{idUser:1,validName:1})
I have an array of ids and I want to get all document of them at once. For that I am writing but it return 0 records.
How can I search using multiple Ids ?
db.getCollection('feed').find({"_id" : { "$in" : [
"55880c251df42d0466919268","55bf528e69b70ae79be35006" ]}})
I am able to get records by passing single id like
db.getCollection('feed').find({"_id":ObjectId("55880c251df42d0466919268")})
MongoDB is type sensitive, which means 1 is different with '1', so are "55880c251df42d0466919268" and ObjectId("55880c251df42d0466919268"). The later one is in ObjectID type but not str, and also is the default _id type of MongoDB document.
You can find more information about ObjectID here.
Just try:
db.getCollection('feed').find({"_id" : {"$in" : [ObjectId("55880c251df42d0466919268"), ObjectId("55bf528e69b70ae79be35006")]}});
I believe you are missing the ObjectId. Try this:
db.feed.find({
_id: {
$in: [ObjectId("55880c251df42d0466919268"), ObjectId("55bf528e69b70ae79be35006")]
}
});
For finding records of multiple documents you have to use "$in" operator
Although your query is fine, you just need to add ObjectId while finding data for Ids
db.feed.find({
"_id" : {
"$in" :
[ObjectId("55880c251df42d0466919268"),
ObjectId("55bf528e69b70ae79be35006")
]
}
});
Just I have use it, and is working fine:
module.exports.obtenerIncidencias386RangoDias = function (empresas, callback) {
let arraySuc_Ids = empresas.map((empresa)=>empresa.sucursal_id)
incidenciasModel.find({'sucursal_id':{$in:arraySuc_Ids}
}).sort({created_at: 'desc'}).then(
(resp)=> {
callback(resp)}
)
};
where:
empresas = ["5ccc642f9e789820146e9cb0","5ccc642f9e789820146e9bb9"]
The Id's need to be in this format : ObjectId("id").
you can use this to transform your string ID's :
const ObjectId = require('mongodb').ObjectId;
store array list in var and pass that array list to find function
var list=db.collection_name.find()
db.collection_name.find({_id:{$in:list}})
db.getCollection({your_collection_name}).find({
"_id" : {
"$in" :
[({value1}),
({value2})
]
}
})
I have recently changed one of my fields from object to array of objects.
In my production I have only 14 documents with this field, so I decided to change those fields.
Is there any best practices to do that?
As it is in my production I need to do it in a best way possible?
I got the document Id's of those collections.like ['xxx','yyy','zzz',...........]
my doc structure is like
_id:"xxx",option1:{"op1":"value1","op2":"value2"},option2:"some value"
and I want to change it like(converting object to array of objects)
_id:"xxx",option1:[{"op1":"value1","op2":"value2"},
{"op1":"value1","op2":"value2"}
],option2:"some value"
Can I use upsert? If so How to do it?
Since you need to create the new value of the field based on the old value, you should retrieve each document with a query like
db.collection.find({ "_id" : { "in" : [<array of _id's>] } })
then iterate over the results and $set the value of the field to its new value:
db.collection.find({ "_id" : { "in" : [<array of _id's>] } }).forEach(function(doc) {
oldVal = doc.option1
newVal = compute_newVal_from_oldVal(oldVal)
db.collection.update({ "_id" : doc._id }, { "$set" : { "option" : newVal } })
})
The document structure is rather schematic, so I omitted putting in actual code to create newVal from oldVal.
Since it is an embedded document type you could use push query
db.collectionname.update({_id:"xxx"},{$push:{option1:{"op1":"value1","op2":"value2"}}})
This will create document inside embedded document.Hope it helps
Data structure is like bellow:
{
"_id" : ObjectId("5031e3f0a606e8ef48c7da6b"),
"hitTime" : [ 1345446896, 1345446943, 1345446991 ],
"tag" : "a"
}
I want to get entries that have hitTime>1345446991 so that I can rank the tag popularity.
How do I do this? Or is there other data structures that are convenient to do this incremental count?
Documentation:
That is, when "value" is inspected, if it is an array, each value in the array is checked.
Using the MongoDB documentation, your query should look something like this:
db.collectionName.find({
hitTime : {
$gt : 1345446991
}
});
I am not sure if this works properly, but you might get the idea. =)