CODEWITHSUNDEEP
node.jsmongodb
IrishGringo
IrishGringo

Reputation: 4044

how to update a mongodb document from node.js?

I am trying to update an array in a mongoDB from a node.js program. I am able to modify the array from within node.js, but I can not get the changes to save.

http://pastebin.com/j0Mnf7jP

I think I am doing something very wrong. assistance would be appreciated...

Upvotes: 12

Views: 65830

Answers (4)

Prathamesh Rasam
Prathamesh Rasam

Reputation: 436

var dbName = 'school'
var tableName = 'classA'
MongoClient.connect(dbName, function(err, db) {
  if (err)
  {
    console.log(err);
  }
  else {

    var collection = db.collection(tableName)
    collection.update({_id:doc._id}, {$set:{scores:zz}}, function(err, result) {
      if (err)
      {
        console.log(err);

      }
      else{
        console.log(result);
      }
    });
  }
});

Upvotes: 1

daemone
daemone

Reputation: 1191

I know it's a bit late to help you now, but maybe others can benefit as new cohorts pass through MongoDB University!

db.schools.update should read db.students.update.

@tymeJV's answer gives the rest:

  • Wrap the $set inside braces: {$set:{scores:zz}}

  • Add a callback function to catch errors:

    db.collection( 'students' ).update (
    { _id : doc._id },
    { $set : { scores:zz } },
    function( err, result ) {
        if ( err ) throw err;
    }
);

Funnily enough, I'm actually doing exactly the same assignment right now! I had a different issue that was answered by reading the docs, but I saw this question while googling for it. Hope I helped someone!

Upvotes: 8

Neo-coder
Neo-coder

Reputation: 7840

I think you should do following code for solving issues 

    var lowScore = 9999.9;
        for ( var i=0; i<doc.scores.length; i++ ) {
            if ( doc.scores[i].type == "homework"
               && doc.scores[i].score < lowScore ) {
                    lowScore = doc.scores[i].score;
            }
        }

and then update your collection using following query

collection.update({ "_id":doc._id }, 
{ $pull : { "scores" : {
$and: [ {"type":"homework"}, { "score":lowScore} ]
} } },
{ "safe":true },
function( err, result ) {
if (err) {
 console.log(err);
  }
} // update callback
);

for more info you can refer here

Upvotes: 0

tymeJV
tymeJV

Reputation: 104775

Change this line:

({_id:doc._id},$set:{scores:zz});

To:

({_id:doc._id}, { $set:{scores:zz}} );

This should also probably be wrapped with a callback, to catch errors:

db.schools.update({_id:doc._id}, {$set:{scores:zz}}, function(err, result) {
    if (err)
        //do something.
});

Upvotes: 11

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