NodeJs And MongoDB

Question

db.getCollection('Leave').find({},{_id:0 , 
Can_It_Be_carry_forwarded:1})

这在MongoDb客户端CMD中完美运行，但在下面的代码中没有

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/Chatbot_Project";
MongoClient.connect(url, function(err, db) {
if (err) throw err;
var dbo = db.db("Chatbot_Project");
dbo.collection('Leave').find({}, {Can_It_Be_carry_forwarded:1}).toArray(function(err, result) {
if (err) 
throw err;
console.log(result);
db.close();
})
});

Answer 1

您的问题是查找方法，您缺少投影字段。 如果只想检索Can_It_Be_carry_forwarded字段，则需要以下内容：{projection:{Can_It_Be_carry_forwarded:1, _id: 0}}作为第二个参数。

类似问题的解决方案：https://stackoverflow.com/a/48294672/4120554

文档：http://mongodb.github.io/node-mongodb-native/3.0/api/Collection.html#find

试试这个：

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/Chatbot_Project";
MongoClient.connect(url, function(err, db) {
if (err) throw err;
var dbo = db.db("Chatbot_Project");
dbo.collection('Leave').find({},{projection:{_id: 0, Can_It_Be_carry_forwarded:1}}).toArray(function(err, result) {
if (err) 
throw err;
console.log(result);
db.close();
})
});