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Mongo script to update an object if its a certain value

I am trying to update a document in Mongo if it has a certain value within a field.
{
"_id" : ObjectId("myObject"),
"source" : "BW",
"sourceTableName" : "myTable",
"tableName" : "tier",
"type" : "main",
"fieldMappings" : [
{
"sourceField" : "tier_id", <~~~~ If this is "tier_id", I want to change it to "trmls_id"
"reportingField" : "bw_id",
"type" : "integer",
"defaultMap" : {
"shouldErrorOnConvert" : false
}
}
]
}
I tried something like
db.getCollection('entityMap').update({"sourceTableName":"myTable"}, {"fieldMappings.0.sourceField":"trmls_id":{$exists : true}}, { $set: { "fieldMappings.0.sourceField": "tier_id" } })
and I think it is failing on the $exists parameter I am setting.
Is there a more cleaner/dynamic way to do this?
The whole query I am trying to formulate is
In the table myTable
I want to check if there is a sourceField that has the value tier_id
If there is tier_id, then change it to trmls_id
Otherwise do nothing
If there is a similar StackOverflow question that answers this, I am happy to explore it! Thanks!

There is a syntax mistake and you can use positional operator $ in update part because you have already selector field in query part,
db.getCollection('entityMap').update(
{
"sourceTableName": "myTable",
"fieldMappings.sourceField": "tier_id" // if this field found then it will go to update part
},
{
$set: {
"fieldMappings.$.sourceField": "trmls_id"
}
}
)

collection update property of embedded document in array

This code uses a loop to $unset the "checked" property of all embedded documents in the "value" array, then $set the one when a condition evaluates to true.
But when the condition is true, the update block failed to update the embedded document by setting a checked: "checked", I know that because meteor:PRIMARY> db.radioOptions.find({}).pretty(); gives the same results before and after.
What am I doing wrong? and how to fix it? Thanks
meteor:PRIMARY> db.radioOptions.find({}).pretty();
{
"_id" : "jXQcsXtedQYotKQXG",
"name" : "optionType",
"value" : [
{
"name" : "1stOption",
"caption" : "1st Option"
},
{
"name" : "2ndOption",
"caption" : "2nd Option"
}
]
}
var doc = RadioOptions.findOne({name: obj.name});
if (typeof doc != 'undefined') {
doc.value.forEach(function (embdoc) {
console.log(embdoc);
RadioOptions.update(
{name: obj.name, 'value.name': obj.value},
{$unset: {'value.$.checked': ""}}
);
if (embdoc.name == obj.value) {
console.log(obj.name + " " + obj.value); //obj.value = 1stOption for example
RadioOptions.update(
{name: obj.name, 'value.name': obj.value}, //obj.name = "optionType"
{$set: {'value.$.checked': "checked"}}
);
}
})
}

Let's say that is was your objective to set the array element with the name "2ndOption" to "checked" and $unset all other array elements. You would then instead do:
var doc = RadioOptions.findOne({name: obj.name});
if (typeof doc != 'undefined') {
// You have to update every element
doc.value.forEach(function (embdoc) {
RadioOptions.update(
{ "_id": doc._id, "value.name": embdoc.name },
{ "$unset": { "value.$.checked": "" } }
)
});
// Then just set the one you want
RadioOptions.update(
{ "_id": doc._id, "value.name": "2ndOption" }, // <-- actually using a variable of course
{ "$set": { "value.$.checked": "checked" } }
)
}
Now if you had actually read all the responses on the duplicate question you were given for your original question:
How to Update Multiple Array Elements in mongodb
Then you would have seen the response there that mentioned the best way to handle all these mutliple updates was using the "Bulk" API methods in the underlying driver. And also has some useful tips on the general process of updating multiple elements.
On the "server" (not in minimongo) is the best place to to this, and all meteor collections have a .rawCollection() method which returns the collection object from the underlying node native driver.
So the general logic is:
Loop all array elements and update to "turn off"
Match the element you want to "turn on"
And best done in Bulk rather than responding back and forth for each update.

MongoDB aggregation: How to extract the field in the results

all!
I'm new to MongoDB aggregation, after aggregating, I finally get the result:
"result" : [
{
"_id" : "531d84734031c76f06b853f0"
},
{
"_id" : "5316739f4031c76f06b85399"
},
{
"_id" : "53171a7f4031c76f06b853e5"
},
{
"_id" : "531687024031c76f06b853db"
},
{
"_id" : "5321135cf5fcb31a051e911a"
},
{
"_id" : "5315b2564031c76f06b8538f"
}
],
"ok" : 1
The data is just what I'm looking for, but I just want to make it one step further, I hope my data will be displayed like this:
"result" : [
"531d84734031c76f06b853f0",
"5316739f4031c76f06b85399",
"53171a7f4031c76f06b853e5",
"531687024031c76f06b853db",
"5321135cf5fcb31a051e911a",
"5315b2564031c76f06b8538f"
],
"ok" : 1
Yes, I just want to get all the unique id in a plain string array, is there anything I could do? Any help would be appreciated!

All MongoDB queries produce "key/value" pairs in the result document. All MongoDB content is basically a BSON document in this form, which is just "translated" back to native code form by the driver to the language it is implemented in.
So the aggregation framework alone is never going to produce a bare array of just the values as you want. But you can always just transform the array of results, as after all it is only an array
var result = db.collection.aggregate(pipeline);
var response = result.result.map(function(x) { return x._id } );
Also note that the default behavior in the shell and a preferred option is that the aggregation result is actually returned as a cursor from MongoDB 2.6 and onwards. Since this is in list form rather than as a distinct document you would process differently:
var response = db.collection.aggregate(pipeline).map(function(x) {
return x._id;
})

MongoDB and Mongoose: How to retrieve nested Object

I have the following documents in my mongodb collection:
{
"current" :
{
"aksd" : "5555",
"BullevardBoh" : "123"
},
"history" :
{ "1" : {
"deleted" : false,
"added" : false,
"date" : "21-08-2014"
}
},
{ "2" : {
"deleted" : false,
"added" : false,
"date" : "01-01-2013"
}
},
"_id" : ObjectId("53f74dad2cbfdc136a07bf16"),
"__v" : 0
}
I have multiple of these documents. Now I want to achieve two things with my Mongoose/Express API.
Query for all nested "current" in each document and retrieve them as JSON objects like such: {"aksd":"5555","BullevardBoh":"123"},{..},{..}.
Retrieve all history revisions (1,2...) where "date" is smaller than a given date.
As you can clearly see this is a kind of versioning I am trying to implement. I would also be interested if this kind of data structure will get indexed by MongoDB and if there is possibly a better way. (e.g. with arrays inside objects?)
This isn't working in MongoDB:
db.ips.findOne({current.aksd: {$exists:true}});

I think the quotes around the field are missing here:
db.ips.findOne({current.aksd: {$exists:true}});
This should work instead:
db.ips.findOne({"current.aksd": {$exists:true}});

While Ritesh's reply was a step in the right direction, I rather wanted to fetch the current object literal and its members inside the document not the whole document.
1.) Query for all nested "current" in each document
db.ips.find({"current":{$exists:true}}, {"current":1});
This is giving back all nested documents where the aksd literal is present:
{ "current" : { "aksd" : "5555", "BullevardBoh" : "123" }, "_id" : ObjectId("53f74dad2cb3dc136a07bf16") }
...
2.) Retrieving history revisions where date is smaller then a given date:
db.ips.find({"history.date": {$lt: "01-01-2014"}},{history:{$elemMatch:{date: {$lt:"01-01-2014"}}}});
Giving back the wanted nested date literal(s):
{ "historie" : [ { "date" : "01-01-2013", "added" : false, "deleted" : false } ], "_id" : ObjectId("53faf20f399a954b2b7736b6") }

how to push a dictionary to a nested array with mongodb?

i have data that looks like this in my database
> db.whocs_up.find()
{ "_id" : ObjectId("52ce212cb17120063b9e3869"), "project" : "asnclkdacd", "users" : [ ] }
and i tried to add to the 'users' array like thus:
> db.whocs_up.update({'users.user': 'usex', 'project' : 'asnclkdacd' },{ '$addToSet': { 'users': {'user':'userx', 'lastactivity' :2387843543}}},true)
but i get the following error:
Cannot apply $addToSet modifier to non-array
same thing happens with push operator, what im i doing wrong?
im on 2.4.8
i tried to follow this example from here:
MongoDB - Update objects in a document's array (nested updating)
db.bar.update( {user_id : 123456, "items.item_name" : {$ne : "my_item_two" }} ,
{$addToSet : {"items" : {'item_name' : "my_item_two" , 'price' : 1 }} } ,
false ,
true)
the python tag is because i was working with python when i ran into this, but it does nto work on the mongo shell as you can see
EDIT ============================== GOT IT TO WORK
apparently if i modify the update from
db.whocs_up.update({'users.user': 'usex', 'project' : 'asnclkdacd' },{ '$addToSet': { 'users': {'user':'userx', 'lastactivity' :2387843543}}},true)
to this:
db.whocs_up.update({'project' : 'asnclkdacd' },{ '$addToSet': { 'users': {'user':'userx', 'lastactivity' :2387843543}}},true)
it works, but can anyone explain why the two do not achieve the same thing, in my understanding they should have referenced the same document and hence done the same thing,
What does the addition of 'users.user': 'userx' change in the update? does it refer to some inner document in the array rather than the document as a whole?

This is a known bug in MongoDB (SERVER-3946). Currently, an update with $push/$addToSet with a query on the same field does not work as expected.
In the general case, there are a couple of workarounds:
Restructure your update operation to not have to query on a field that is also to be updated using $push/$addToSet (as you have done above).
Use the $all operator in the query, supplying a single-value array containing the lookup value. e.g. instead of this:
db.foo.update({ x : "a" }, { $addToSet : { x : "b" } }, true)
do this:
db.foo.update({ x : { $all : ["a"] } }, { $addToSet : { x : "b" } } , true)
In your specific case, I think you need to re-evaluate the operation you're trying to do. The update operation you have above will add a new array entry for each unique (user, lastactivity) pair, which is probably not what you want. I assume you want a unique entry for each user.
Consider changing your schema so that you have one document per user:
{
_id : "userx",
project : "myproj",
lastactivity : 123,
...
}
The update operation then becomes something like:
db.users.update({ _id : "userx" }, { $set : { lastactivity : 456 } })
All users in a given project may still be looked up efficiently by adding a secondary index on project.
This schema also avoids the unbounded document growth of the above schema, which is better for performance.