CODEWITHSUNDEEP
javascriptnode.jsmongodb
user7227230
user7227230

Reputation: 69

mongoDB - cursor only updates 1 document using node.js driver

I'm using mongoDB (3.4) with a node.js driver and I'm trying to update a field in all documents contained within "items_collection". I've tried a couple of different approaches but I can't seem to find a solution which correctly updates ALL documents. Below is the code I've currently got:

var cursor = db.collection('items_collection').find();
cursor.on("end", function() {
    console.log("Finished. Closing db...");
    db.close();
}); 

cursor.on("err", function() {
    console.dir("Error on:" + err);
    throw err;
});

cursor.on("data", function(doc) {
    cursor.pause();

    var newTitle = getTitleFromDescription(doc.description);
    db.collection('items_collection').update({_id: doc._id}, {$set:{title: newTitle}}, {multi:true});

    cursor.resume();
});

This seems reasonably sane to me, however it's only ever the first document which gets its title updated to "test_title". I must be missing something obvious here right?

Thanks.

Upvotes: 0

Views: 321

Answers (2)

Asif Saeed
Asif Saeed

Reputation: 2045

Use update instead of save and use multi : true for multiple document udpates:

db.collectionname.update( {}, { $set:{ title : "newvalue" } }, { multi : true } );

All updates in MongoDB are, by default, singular. you must add a multi : true

cursor.on("data", function(doc) {
    cursor.pause();

    var newTitle = getTitleFromDescription(doc.description);

    console.log(doc._id);
    console.log(newTitle);

    db.collection('items_collection').update({_id: doc._id}, {$set:{title: newTitle}}, {multi:true}).then(function(response){
        console.log(response);  
        console.log('++++++++++++++++++');
        cursor.resume();
    });
});

Upvotes: 2

metame
metame

Reputation: 2640

You can easily do this with a multi-update. Assuming you want to update every document in your collection, you would do:

db.collection("items_collection").update({},{$set:{title: "test_title"},{multi:true} );

The docs explain this clearly here.

Also note that you must update operator expressions for multi-updates. If you were updating a single document, the second parameter to the update method can be a plain object of field:value, but a multi-update has to use an update operator like $set in the example above.

Upvotes: 0

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