I am trying out loopback-connector-couch database operator for deleting multiple records from CouchDB in one shot.
I have records _id in an array
Following the API spec for Loopback model as provided in the below api doc
https://apidocs.strongloop.com/loopback/#persistedmodel-destroyall
persist_model.destroyAll({id:{or:["49c199312b7dce75d69124f9e377a682","49c199312b7dce75d69124f9e377a682"]}},function(err,res){
console.log('records deleted success:'+res);
});
When executing the above code, it does not throw any error but its not deleting any documents
Would appreciate any help on this :)
The correct way is to use inq operator if you want to compare the value with multiple value stored in an array as follows:
persist_model.destroyAll({ id: { inq: [ "49c199312b7dce75d69124f9e377a682", "49c199312b7dce75d69124f9e377a682" ]}},
function(err, res) {
if (err) {
throw err;
}
console.log('records deleted success:' + res);
}
);
You can read more about inq operator here.
Related
I scouted around to find the right solution for inserting a large amount of documents to MongoDB using Mongoose.
My current solution looks like this:
MongoClient.saveData = function(RecordModel, data, priority, SCHID, callback){
var dataParsed = parseDataToFitSchema(data, priority, SCHID);
console.log("Model created. Inserting in batches.");
RecordModel.insertMany(dataParsed)
.then(function(mongooseDocuments) {
console.log("Insertion was successful.");
})
.catch(function(err) {
callback("Error while inserting data to DB: "+err);
return;
})
.done(function() {
callback(null);
return;
});
}
But it appears to me there are other offered solutions out there. Like this one:
http://www.unknownerror.org/opensource/Automattic/mongoose/q/stackoverflow/16726330/mongoose-mongodb-batch-insert
Using collection.insert. How is that different to the Model.insertMany?
Same goes for update, my previous question: What is the right approach to update many records in MongoDB using Mongoose
Asks how do I update big chunk of data with Mongoose, defined by _id. The answer suggests to use collection.bulkWrite while I am under impression Model.insertMany can do it too.
How can I create the not contains query that returns true if the item does not contain a certain value. I'm running mongoDB if it is relevant.
I can use the contains successfully however receive an error when I introduce the not. I've tried it with find and where but get the same regex error both times. I can add the exact error if its relevant.
Working version:
model.find({attribute: {'contains': value}})
.exec(function(err, users) {
// happy code
});
The following complains about some regex error:
model.find({attribute: {not: {'contains': value}}})
.exec(function(err, users) {
// sad code
});
There was an issue raised and closed in 2013 about this. Maybe something changed recently?
https://github.com/balderdashy/waterline/issues/22
Alexei, I don't think this is supported by waterline currently. There is a related issue which is marked as feature and that you can track:
https://github.com/balderdashy/waterline/issues/666
So far, you can only use native feature of Mongodb I think.
Model.native(function(err, collection) {
collection.find({
"attribute" : {
$ne : value, //Not Equal
//OR
$nin : [value1, value2]// Not In
}
}).toArray(function(err, docs) {
if (err) return callback(err, docs);
res.json(null, docs);
});
});
Save() giving me error like "Object has no method 'save'"
Country.update({id:req.param('country_id')},model).exec(function(err,cntry){
if(err) return res.json(err);
if(!cntry.image){
cntry.image = 'images/countries/'+filename;
cntry.save(function(err){ console.log(err)});
}
})
Any Idea about how to save model within update query . ??
Assuming you're using Waterline and sails-mongo, the issue here is that update returns an array (because you can update multiple records at once), and you're treating it like a single record. Try:
Country.update({id:req.param('country_id')},model).exec(function(err,cntry){
if(err) return res.json(err);
if(cntry.length === 0) {return res.notFound();}
if(!cntry[0].image){
cntry[0].image = 'images/countries/'+filename;
cntry[0].save(function(err){ console.log(err)});
}
});
This seems to me an odd bit of code, though; why not just check for the presence of image in model before doing Country.update and alter model (or a copy thereof) accordingly? That would save you an extra database call.
When using mongoose (3.8) to update the database directly the callback function receives 3 parameters, none of then is a mongoose object of the defined model. The parameters are:
err is the error if any occurred
numberAffected is the count of updated documents Mongo reported
rawResponse is the full response from Mongo
The right way is, first you fetch and then change the data:
Country.findOne({id: req.param('country_id')}, function (err, country) {
// do changes
})
Or using the update method, the way you intended:
Country.update({id: req.param('country_id'), image: {$exists: false}}, {image: newValue}, callback)
So I have a model that is for a recipe where it has a relation of 'ingredients' and that is just an array of ObjectIds. When I run the following query on mongo shell it works fine and returns all my data.
Example model :
{
"name": "...",
"_id": ObjectId("530ca903746515c0161e6b9f"),
"ingredients": [
ObjectId("53069363ff7447a81a3a7a1d"),
ObjectId("53069363ff7447a81a3a7a17")
]
}
Query:
db.drink.find({"ingredients":{"$in":[ObjectId("53069364ff7447a81a3a7a87"), ObjectId("530fb948c1a3ff480d58e43c")]}});
Using sails.js though their waterline orm, they don't really have a way to query this though or at least through any possible google search that I can find. So trying to use the native driver I have something like the following -
var ings = new Array();
for (var i in req.body) {
ings.push(new ObjectID(req.body[i].toString()));
}
Drink.native(function(err, collection){
if(err){
return res.send(err, 500);
} else {
collection.find({"ingredients":{"$in":ings}}).toArray(function(err, data){
console.log(data);
});
}
});
The thing is the data array returned in the callback is always empty. If I check the 'ings' array it is an array of objectids so I am not sure why it won't return any data. If I remove the json object in the 'find' function it does return everything. Anyone have any idea how to make this query return data when using sails.js?
The code above actually is working it was an internal data issue on the mongodb where IDs were not matching between relations. When the relations were rebuilt all is working as it should be.
I'm writing a little application which scores keywords. So if "beirut" and "education" get entered in, if they haven't been seen before, I want to create a mongo entry, and give them a score of 1. If they have, I want to increment their score by one. I'm trying to do this with one update command, but I think I might be doing it wrong.
Ranking is the object representing the database
"key" is the keyword
rankingdb.update(
{keyword:key},
{keyword:key, {$inc:{score:1}}},
{upsert:true, safe:false},
function(err, data) {
if (err) {
console.log(err);
}
else {
console.log("score succeeded");
}
}
);
SyntaxError: Unexpected token {
Can you not create a brand new document with an increment?
Your general approach is right, but as the error message suggests, you've got a syntax problem in your code.
Try this instead:
rankingdb.update(
{keyword: key},
{$inc: {score: 1}},
{upsert: true, safe: false},
function(err,data){
if (err){
console.log(err);
}else{
console.log("score succeded");
}
}
);
When an upsert needs to create a new object it combines the fields from the selector (first parameter) and the update object (second parameter) when creating the object so you don't need to include the keyword field in both.
Note that update() is deprecated in the 2.0 driver, so you should now use either updateOne() or updateMany().