[英]How to get documents from MongoDB?
I have a database on MongoDB Atlas. 我在MongoDB Atlas上有一个数据库。 Using NodeJS I established a connection and tried to get some data. 使用NodeJS,我建立了一个连接并尝试获取一些数据。
const client = new MongoClient(uri, { useNewUrlParser: true });
client.connect(err => {
if(err){
console.log(err)
return res.status(400).json({msg:"Error occured while trying to connect to database", error: err})
}
const collection = client.db("first-test").collection("members")
// perform actions on the collection object
// console.log(collection)
collection.forEach(member => {
console.log(member)
})
client.close();
return res.status(200).json({msg:"success"})
});
When I tried console.log(collection)
I got big object as output (I guess it's what's called a cursor) 当我尝试console.log(collection)
我得到了一个大对象作为输出(我想这就是所谓的游标)
Collection {
s: {
pkFactory: [Function: ObjectID] {
index: 4705316,
createPk: [Function: createPk],
createFromTime: [Function: createFromTime],
createFromHexString: [Function: createFromHexString],
isValid: [Function: isValid],
ObjectID: [Circular],
ObjectId: [Circular]
},
db: Db {
_events: [Object: null prototype] {},
_eventsCount: 0,
_maxListeners: undefined,
s: [Object],
serverConfig: [Getter],
bufferMaxEntries: [Getter],
databaseName: [Getter]
},
// And so on ....
When I tried collection.forEach(member => console.log(member))
I got an error TypeError: collection.forEach is not a function
. 当我尝试collection.forEach(member => console.log(member))
,出现错误TypeError: collection.forEach is not a function
。 My question is, how can get my data from the database? 我的问题是,如何从数据库中获取数据?
You are missing the step to "find" all the documents. 您缺少“查找”所有文档的步骤。
ex from w3schools : 来自w3schools:
dbo.collection("customers").find({}).toArray(function(err, result) {
if (err) throw err;
console.log(result);
db.close();
});
I recommend to use mongoose, it's a lot simpler. 我建议使用猫鼬,这要简单得多。
But the actual code is 但是实际的代码是
const client = new MongoClient(uri, { useNewUrlParser: true });
client.connect(err => throw err);
client.members.find({},(err, res)=>{
console.log(res);
})
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.