angularjs - 如何使用node.js将数组插入mongodb

Question

我有一个类似 [ 570dec75cf30bf4c09679deb, 56fe44836ce2226431f5388f ] 的数组。现在我想将其插入名为 notifications 的新集合，例如

{
  "_id": ObjectId("57bd39c9734ff3602a312b33"),
  "userId": ObjectId("570dec75cf30bf4c09679deb") 
}

and

{
  "_id": ObjectId("57bd39c8734ff3602a312b32"),
  "userId": ObjectId("56fe44836ce2226431f5388f ") 
}

我在node.js中编写了一个查询来插入它，但它像这样插入数组的最后一个元素两次

{
  "_id": ObjectId("57bd39c9734ff3602a312b33"),
  "userId": ObjectId("56fe44836ce2226431f5388f ") 
}

and

{
  "_id": ObjectId("57bd39c8734ff3602a312b32"),
  "userId": ObjectId("56fe44836ce2226431f5388f ") 
}

我这样写的查询

app.js

router.post('/creatList', function(req,res){
    console.log(req.body.email);
    var emails = req.body.email;

    if(req.body.wData.wishListType == 'Shared'){
        var findUsers = function(db, callback) {
            var cursor;
            cursor = db.collection('users').find({email: { $in: emails }})

            cursor.toArray(function(err, docs){
                if(err){
                    callback(new Error("Some problem"));
                } else {
                    callback(null,docs);
                } 
            });     
        };

        MongoClient.connect(config.database, function(err, db) {
            assert.equal(null, err);
            findUsers(db, function(err,docs) {
                db.close();
                console.log(docs);

                for(var key in docs){
                    console.log(key);
                    var ids = docs[key]._id;
                    console.log(ids);

                    var insertDocument = function(db, callback) {
                        db.collection('notifications').insert({
                            "userId" : ids,
                        },function(err, result) {
                            assert.equal(err, null);
                            console.log("Inserted a document into the notifications collection.");
                            callback();
                        });
                    };

                    MongoClient.connect(config.database, function(err, db) {
                        assert.equal(null, err);
                        insertDocument(db, function() {
                            db.close();
                        });
                    });
                }
            });
        }); 
      });

Answer 1

您基本上需要重新映射 users.find() 的结果，以便它们与您的通知集合的架构匹配。这应该有效:

var docsToInsert = docs.map(function (doc) {
        // this assumes your users collection has an _id that you actually want to use as the reference for you notifications.userId field
        // actually, you probably want "return {"userId": ObjectID(doc._id)};" since you are using the native mongodb api
        return { "userId": doc._id };
});

所以，稍微简化一下剩下的内容，那就是:

router.post('/creatList', function (req, res) {
    console.log(req.body.email);
    var emails = req.body.email;

    if (req.body.wData.wishListType == 'Shared') {
        var findUsers = function (db, callback) {
            var cursor;
            cursor = db.collection('users').find({ email: { $in: emails } });

            cursor.toArray(function (err, docs) {
                if (err) {
                    callback(new Error("Some problem"));
                } else {
                    callback(null, docs);
                }
            });
        };

        MongoClient.connect(config.database, function (err, db) {
            assert.equal(null, err);
            findUsers(db, function (err, docs) {
                db.close();
                console.log(docs);

                var docsToInsert = docs.map(function (doc) {
                    // this assumes your users collection has an _id that you actually want to use as the reference for you notifications.userId field
                    // actually, you probably want "return {"userId": ObjectID(doc._id)};" since you are using the native mongodb api
                    return { "userId": doc._id };
                });

                MongoClient.connect(config.database, function (err, db) {
                    assert.equal(null, err);
                    db.collection("notifications").insert(docsToInsert, function (err, result) {
                        if (err) {
                            // handle the err however you like 
                            throw err;
                        }
                        db.close();
                    });
                });
            });
        });
    }
});