How can I make Mongoose (running on Node.js) run an arbitrary query string?

Question

I have a table called "files" wherein each object has a name, a parent, and some other fields. What I want to do is, given a filename, find the path to root (root occurs when parent is '').

I have a query that works perfectly when run in the Mongo terminal:

var currentFile = parent;
var queue = [];

while(currentFile !== '') {
    var file = db.files.find( { name: currentFile } );
    currentFile = file[0].parent;
    queue.push(currentFile);
}

Unfortunately, however, Mongoose does not allow (as far as I have seen from the documentation) arbitrary string queries. I could do it if Mongoose allowed for synchronous queries, but I cannot seem to find that ability either.

SOLVED

After re-reading the first comment, I found that to achieve what I needed, I needed to add a callback to the parameters that gets called when currentFile is empty

if(currentFile === '') {
    callback();
else
    recursiveFunc(currentFile, callback);

I also added the field of 'path' in case I decide to be a little bit more efficient :)

Thank you guys for all the help!

Jamund Ferguson · Accepted Answer · 2011-12-29 20:31:30Z

1

What about a recursive function?

var queue = [];
var currentFile = parent;
function findStuff(currentFile) {
    File.findOne({name: currentFile}, function(err, file) {
        currentFile = file[0].parent;
        queue.push(currentFile);
        findStuff(currentFile)
    })
}

Also as or "arbitrary query string", I'm not sure what you mean. It's standard mongo syntax. If you want to hit the node-mongodb-native driver directly you can always do something like this. It's still async though.... https://github.com/christkv/node-mongodb-native

File.collection.find({}, function(err, files) {});

What about something simpler? Sorry, I'm not fully understanding your intentions.

var queue = [];
var currentFile = parent;
File.find({name: currentFile}, function(err, files) {
    files.forEach(function(file) {
         queue.push(file.parent)
    })
})

edited Dec 29, 2011 at 20:31

answered Dec 29, 2011 at 20:06

Jamund Ferguson

17k3 gold badges47 silver badges51 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user1121823 Over a year ago

How could I call this and ensure that the array that I get after the call contains all of the elements? By "arbitrary query string," I mean send a string of BSON (with some JavaScript) to the MongoDB server, execute it, and get the results, a la MySQL.

Jamund Ferguson Over a year ago

ooooh. let me change it a little.

mpobrien · Accepted Answer · 2011-12-30 20:15:04Z

0

Perhaps you could avoid this entirely by storing an additional field in your documents that contains the path to root - say, an array of ObjectId's called path_to_root.

Then when inserting a new document, just copy the parent's value for path_to_root and append the parent's _id to it, and use this as path_to_root for the newly inserted document. With this strategy you could quickly query all the documents for the path back to root using a mongodb $in query.

Not sure if this could work for you without understanding the larger context, but just throwin it out there.

answered Dec 30, 2011 at 20:15

mpobrien

4,9621 gold badge35 silver badges36 bronze badges

Collectives™ on Stack Overflow

How can I make Mongoose (running on Node.js) run an arbitrary query string?

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related