I have a graph consisting of 3 document collections and 2 edge collections. I want to perform filtering from one doc collection but need to show the result from all three doc collections.
Graph: AssetWorkTime
Documents Collection: assetnew (consists name of asset), timenew (consists the start date of renovation), and Work (consists type of renovation)
Edge Collection: AssetRenoTimeNew (Connecting assetnew and timenew) and WorkTimeNew (Connecting timenew and Work)
This a part of my graph
FOR c IN timenew
FILTER c.startdate>="2020-01-01"
FOR v, e, p IN 1..1 outbound c GRAPH 'AssetWorkTime'
RETURN {AssetName:v.AssetName, Date:c.startdate, RenoJob:v.WorkName}
This is the query that I have done. I want to know which assets have gone through renovation after 1/1/2020 and what type of renovation that has been done.
This is the result that I got. The result are correct except for it does not show the name of the assets
I've gone through the documentation and other questions in stackoverflow but couldn't find a way to get this. Thanks!
Related
Desired result
I am trying to query my collection and obtain every unique combination of a batch and entry code. I don't care about anything other than these fields, the parent objects do not matter to me.
What I have tried
I tried running:
db.accountant_ledgers.aggregate( [ {"$group": { "_id": { entryCode: "$actions.entry.entryCode", batchCode: "$actions.entry.batchCode" } } } ]);
Problem
I get unexpected results when I run that query. I'm looking for a list of every unique combination of batch and entry codes, but instead I get a list of arrays? Perhaps these are the results I'm looking for, but I have no idea how to read them if they are.
Theory
I think perhaps this could have to do with the fact that these fields are nested. Each object has several actions, each action has several entries. I believe that the result from that query is just the aggregated entry and batch codes found in each object. I don't know how long the list of results is, but I'd guess it's the same number as the total number of objects in my collection (~90 million).
EDIT: I found out that there are only 182 results from my query, which is clearly significantly smaller than 90 million. My new theory is that it has found all unique objects, with the criteria for "uniqueness" being the list of the batch and entry codes that appear in their actions, which makes sense. There should be a lot of repetition in the collection.
Question
How can I achieve the result I'm looking for? I'm expecting something like:
FEE, MG
EXN, WT
ACH, 9C
...etc
Notes
I apologize if this is a bad question, I'm not sure how else to frame it. Let me know if I can improve my question at all.
Picture below shows the results of the query.
EDIT FOR ADDITIONAL INFORMATION
I can't share any sample documents, but the general structure of the data is shown (crudely) in the below image. Each Entity has several Actions, each Action has one Entry and each Entry has one Batch code and one Entry code.
List item
You are getting a list of documents (each is a map or a hash), not a list of arrays.
The GUI you are using is trying to show you the contents of each document on the top level which is maybe what is confusing.
If you run the query in mongo shell you should see a list of documents.
It looks like your inputs are documents where entry code and batch code are arrays, if so:
Edit your question to include sample documents you are querying as text
You could use $unwind to flatten those arrays before using $group.
QUERYING MONGODB: RETREIVE SHOPS BY NAME AND BY LOCATION WITH ONE SINGLE QUERY
Hi folks!
I'm building a "search shops" application using MEAN Stack.
I store shops documents in MongoDB "location" collection like this:
{
_id: .....
name: ...//shop name
location : //...GEOJson
}
UI provides to the users one single input for shops searching. Basically, I would perform one single query to retrieve in the same results array:
All shops near the user (eventually limit to x)
All shops named "like" the input value
On logical side, I think this is a "$or like" query
Based on this answer
Using full text search with geospatial index on Mongodb
probably assign two special indexes (2dsphere and full text) to the collection is not the right manner to achieve this, anyway I think this is a different case just because I really don't want to apply sequential filter to results, "simply" want to retreive data with 2 distinct criteria.
If I should set indexes on my collection, of course the approach is to perform two distinct queries with two distinct mehtods ($near for locations and $text for name), and then merge the results with some server side logic to remove duplicate documents and sort them in some useful way for user experience, but I'm still wondering if exists a method to achieve this result with one single query.
So, the question is: is it possible or this kind of approach is out of MongoDB purpose?
Hope this is clear and hope that someone can teach something today!
Thanks
I am working on a database of Polish verbs and I'd like to find out how to display my results such that each verb conjugation appears in the following order: 1ps (1st person singular), 2ps, 3ps, 1ppl (1st person plural, etc.), 2ppl, 3ppl. It displays fine when I insert documents:
verb "żyć/przeżyć" conjugation as array and nested document
But when I go to perform queries it jumbles all the array elements up, in the first case (I want to see them in order of array indices), and sorts the nested document elements into alphabetical order (whereas I want to see them in the order in which they were inserted).
verb "żyć/przeżyć" conjugation array/document query
This should be an easy one to solve, I hope this comes across as a reasonable beginner's question. I have searched for answers but couldn't find much info on this topic. Any and all help is greatly appreciated!
Cheers,
LC.
Your screenshots highlight two different views in MongoDB Compass.
The Schema view is based on a sampling of multiple documents and the order of the fields displayed cannot be specified. The schema analysis (as at Compass 1.7) lists fields in case-insensitive alphabetical order with the _id field at the top. Since this is an aggregate schema view based on multiple documents, the ordering of fields is not expected to reflect individual document order.
If you want to work with individual documents and field ordering you need to use the Documents view, as per your second screenshot. In addition to displaying the actual documents, this view allows you to include sort and skip options for queries:
I want to compare two very big collection, the main of the operation is two know what element is change or deleted
My collection 1 and 2 have a same structure and have more 3 million records
example :
record 1 {id:'7865456465465',name:'tototo', info:'tototo'}
So i want to know : what element is change, and what element is not present in collection 2.
What is the best solution to do this?
1) Define what equality of 2 documents means. For me it would be: both documents should contain all fields with exact same values given their ids are unique. Note that mongo does not guarantee field order, and if you update a field it might move to the end of the document which is fine.
2) I would use some framework that can connect to mongo and fetch data at the same time converting it to a map-like data structure or even JSON. For instance I would go with Scala + Lift record (db.coll.findAll()) + Lift JSON. Lift JSON library has Diff function that will give you a diff of 2 JSON docs.
3) Finally I would sort both collections by ids, open db cursors, iterate and compare.
if the schema is flat in your case it is, you can use a free tool to compare the data(dataq.io) in two tables.
Disclaimer : I am the founder of this product.
So I have an interesting use case that I'm stuck trying to find a efficient mongo query for.
To begin, I have 12,000 categories with 100,000 posts. I need to randomly select a 100 pairs of posts, from random categories. The pairs are randomly selected from categories, but each pair must have both posts belonging to the same category.
Users look at each pair to rate and once they finish looking at the 100, they fetch another 100 random posts (preferably not any of the same pairs they've already seen).
So the requirements are:
Fetch 100 pairs of posts randomly from a random set of categories
Optional requirements:
Not to return the same pairs they've already rated
Mongo Collections
Users
Categories
Posts
CategoryId
Ratings (embedded collection in posts)
How would I do this in Mongo... should I move some of this data off of mongo to another db if it's easier?
Yes. Very interesting question. My suggestion is to put a randomVal field on your post documents. Then you can sort on {CategoryId: 1, randomVal: 1}. The result will be a cursor that groups all the posts by CategoryId but randomly within that grouping. If you conceptually think of this as an array, you can pick all the even indexed posts, and pair them with an odd neighbor to get unique random pairs within categories.
I think that how to select the random pairs from this list will take some experimentation, but my gut instinct is that the best approach would be to have a separate process that periodically caches a collection of pairs which are sorted by a separate randomVal2. The user facing queries would just increment through this pairs collection 100 at a time.
I think you can achieve this in two query. First you need to use aggregation framework and do a map reduce operation on Posts collection. In the map phase use category id as the key and emit post ids to reducer.
In the reduce phase choose two random id from each category. In the end of the map reduce you will have a list of Post ids. Then retrieve those posts from Posts collection.
Add a ratedBy field to Post document and when user rated a post add his or her userName to ratedBy field. Then use that field as a filter to your map reduce command in the first place so that you don't bring already rated documents to user.
Good luck