您如何使用官方的mongo-go-driver连接到MongoDB Atlas [重复]

此问题已经存在 在这里有答案</ p>

  • 如何使用mongodb 3.6中的新URL从golang连接

    </ span>

    </ li>

    </ ul>

    </ div>

    I' 我看着教程与官方 mongo-go-一起发布 驱动程序,连接示例使用 localhost </ code> </ p>

    client上的MongoDB服务器 选项:= options.Client()。ApplyURI(“ mongodb:// localhost:27017”)
    </ code> </ pre>

    但是,新的托管MongoDB服务地图集需要用户名和密码才能登录。 连接字符串的格式为</ p>

      mongodb:// [username:password @] host1 [/ [database] [?options]] 
    </ code> </ pre >

    ,但是驱动程序中没有Golang示例 </ p>

    这样的例子,我想知道,什么是最好的登录Atlas的方法,而无需将密码硬编码到将发布在Github上的源文件中? </ p>
    </ div>



This question already has an answer here:

I'm looking at the tutorial offered in conjunction with the release of the official mongo-go-driver and the connection example uses a MongoDB server on localhost

// Set client options
clientOptions := options.Client().ApplyURI("mongodb://localhost:27017")

However, the new hosted MongoDB service Atlas requires username and password to login. The connection string takes the format


but there is no Golang example in the driver examples for Atlas.

So I'm wondering, what is the best way to log into Atlas without hard coding a password into a source file that will be posted on Github?


dongwei1895 完全没有什么不同。实际上,它是官方的MongoDBGo驱动程序(答案的第二部分甚至认为问题使用mgo),并且实际上是推荐的连接方式。就像我说的只是众多之一。人们使用连接URI已有很多年了。
大约一年之前 回复
dony39517 我很高兴您链接到的答案是相似的,但是在许多方面却是不同的。我认为这个问题对Atlas和mongo-go-driver都是一个独立的贡献。具体区别:(1)另一个问题在问题中使用了mgo驱动程序,而mongo-go驱动程序仅在答案之一中进行了讨论;(2)有关使用SRV进行更复杂连接的另一个问题,而该问题与为初学者提供更清晰服务的基本连接有关;(3)该问题提供了完整的答案。谨请您删除重复的作业。
大约一年之前 回复
douqin3245 可能没有GoLang示例,但是对于所有语言,连接URI格式的处理方式完全相同。常见的“语言教程”通常仅给出有关您连接到MongoDB本地实例的假设的示例。我在此处发布的大多数答案也只显示了本地连接字符串,并且没有凭据,但这不会使它们对于与远程主机和凭据一起使用无效。您只需交换URI的内容。而且实际上有许多现有的答案和示例。
大约一年之前 回复


I am hosting my test Atlas cluster on AWS so I wanted to have similar credential management to the AWS process. From the AWS credentials page:

The default provider chain looks for credentials in the following order:

  1. Environment variables.

  2. Shared credentials file.

  3. If your application is running on an Amazon EC2 instance, IAM role for Amazon EC2.

Therefore, I wanted to implement the environment veriable for my simple login to Atlas example. Code below assumes that the following line has been issued at the command line

export MONGO_PW='<your Atlas admin user password>'

Then the following program will verify your connection

package main

import (


var username = "<username>"
var host1 = "<atlas host>"  // of the form foo.mongodb.net

func main() {

    ctx := context.TODO()

    pw, ok := os.LookupEnv("MONGO_PW")
    if !ok {
        fmt.Println("error: unable to find MONGO_PW in the environment")
    mongoURI := fmt.Sprintf("mongodb+srv://%s:%s@%s", username, pw, host1)
    fmt.Println("connection string is:", mongoURI)

    // Set client options and connect
    clientOptions := options.Client().ApplyURI(mongoURI)
    client, err := mongo.Connect(ctx, clientOptions)
    if err != nil {

    err = client.Ping(ctx, nil)
    if err != nil {

    fmt.Println("Connected to MongoDB!")

From here the rest of the tutorial linked in my original question goes smoothly.

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<div class="post-text" itemprop="text"> <p>I'm using mongo-go-driver, parallel connect several ports to check whether the port is listened by mongodb </p> <p>go version 1.12.3 mongo-go-driver v1.0</p> <pre class="lang-golang prettyprint-override"><code>type BaseServerStatus struct { Host string `bson:"host"` Version string `bson:"version"` Process string `bson:"process"` Pid int64 `bson:"pid"` Uptime int64 `bson:"uptime"` UptimeMillis int64 `bson:"uptimeMillis"` UptimeEstimate int64 `bson:"uptimeEstimate"` LocalTime time.Time `bson:"localTime"` } func GetBaseServerStatus(ip, port string) (srvStatus *BaseServerStatus, err error) { opts := options.Client() opts.SetDirect(true) opts.SetServerSelectionTimeout(1 * time.Second) opts.SetConnectTimeout(2 * time.Second) opts.SetSocketTimeout(2 * time.Second) opts.SetMaxConnIdleTime(1 * time.Second) opts.SetMaxPoolSize(1) url := fmt.Sprintf("mongodb://%s:%s/admin", ip, port) opts.ApplyURI(url) ctx, _ := context.WithTimeout(context.Background(), 2*time.Second) conn, err := mongo.Connect(ctx, opts) if err != nil { fmt.Printf("new %s:%s mongo connection error: %v ", ip, port, err) return } defer conn.Disconnect(ctx) err = conn.Ping(ctx, nil) if err != nil { fmt.Printf("ping %s:%s ping error: %v ", ip, port, err) return } sr := conn.Database("admin").RunCommand(ctx, bson.D{{"serverStatus", 1}}) if sr.Err() != nil { fmt.Printf("get %s:%s server status error: %v ", ip, port, sr.Err()) return } srvStatus = new(BaseServerStatus) err = sr.Decode(srvStatus) return } func main() { var wg sync.WaitGroup //ips := []string{"xxx.xxx.xxx.xxx:22"} ips := []string{"xxx.xxx.xxx.xxx:22", "xxx.xxx.xxx.xxx:80", "xxx.xxx.xxx.xxx:7005", "xxx.xxx.xxx.xxx:7017", "xxx.xxx.xxx.xxx:7006", "xxx.xxx.xxx.xxx:7016", "xxx.xxx.xxx.xxx:7018", "xxx.xxx.xxx.xxx:7014", "xxx.xxx.xxx.xxx:199", "xxx.xxx.xxx.xxx:8182", "xxx.xxx.xxx.xxx:7015", "xxx.xxx.xxx.xxx:7022", "xxx.xxx.xxx.xxx:7013", "xxx.xxx.xxx.xxx:7020", "xxx.xxx.xxx.xxx:9009", "xxx.xxx.xxx.xxx:7004", "xxx.xxx.xxx.xxx:7008", "xxx.xxx.xxx.xxx:7002", "xxx.xxx.xxx.xxx:7021", "xxx.xxx.xxx.xxx:7007", "xxx.xxx.xxx.xxx:7024", "xxx.xxx.xxx.xxx:7010", "xxx.xxx.xxx.xxx:7011", "xxx.xxx.xxx.xxx:7003", "xxx.xxx.xxx.xxx:7012", "xxx.xxx.xxx.xxx:7009", "xxx.xxx.xxx.xxx:7019", "xxx.xxx.xxx.xxx:8001", "xxx.xxx.xxx.xxx:7023", "xxx.xxx.xxx.xxx:111", "xxx.xxx.xxx.xxx:7001", "xxx.xxx.xxx.xxx:8002", "xxx.xxx.xxx.xxx:19313", "xxx.xxx.xxx.xxx:15772", "xxx.xxx.xxx.xxx:19777", "xxx.xxx.xxx.xxx:15778", "xxx.xxx.xxx.xxx:15776"} for _, ip := range ips { wg.Add(1) //time.Sleep(3 * time.Second) go func(addr string) { fmt.Printf("start to probe port %s ", addr) GetBaseServerStatus(strings.Split(addr, ":")[0], strings.Split(addr, ":")[1]) wg.Done() }(ip) } wg.Wait() fmt.Println("scan end") time.Sleep(20 * time.Second) } </code></pre> <p>however, run this code ,it consume 26GB memory I use pprof to diagnose, see below</p> <p>Showing top 10 nodes out of 15 flat flat% sum% cum cum% 26.29GB 96.86% 96.86% 26.29GB 96.86% go.mongodb.org/mongo-driver/x/network/connection.(*connection).ReadWireMessage</p> </div>

如何使用mongodb / mongo-go-driver执行有效的分页

<div class="post-text" itemprop="text"> <p>I read in the following article that it is more efficient to use the natural ordering of <code>_id</code> to perform paging because skip always starts from the beginning from the collection</p> <p><a href="https://www.codementor.io/arpitbhayani/fast-and-efficient-pagination-in-mongodb-9095flbqr" rel="nofollow noreferrer">https://www.codementor.io/arpitbhayani/fast-and-efficient-pagination-in-mongodb-9095flbqr</a> </p> <pre><code>// Page 1 db.students.find().limit(10) // Page 2 last_id = ... # logic to get last_id db.students.find({'_id': {'$gt': last_id}}).limit(10) </code></pre> <p>But I have no idea how to perform the above using the <code>mongodb/mongo-go-driver</code>.</p> </div>


<div class="post-text" itemprop="text"> <p>Long, long ago, when we were using mgo.v2, we created some wrapper functions that copied the session, set the read pref and returned that for consumption by other libraries, e.g.</p> <pre class="lang-golang prettyprint-override"><code>func NewMonotonicConnection() (conn *Connection, success bool) { conn := &amp;Connection{ session: baseSession.Copy(), } conn.session.SetMode(mongo.Monotonic, true) return conn, true } </code></pre> <p>We now just pass the default client (initialized using mongo.Connect and passed into a connection singleton) in an init function and then consumed like this:</p> <pre class="lang-golang prettyprint-override"><code>func NewMonotonicConnection() (conn *Connection, success bool) { conn = defaultConnection return conn, true } </code></pre> <p>My understanding is that to leverage connection pooling, you need to use the same client (which is contained in defaultConn), and session is now implicitly handled inside of the <code>.All()</code>/cursor teardown. Please correct me if I'm wrong here.</p> <p>It would be nice if we could still set the readpref on these connections (e.g. set NearestMode on this connection before returning), but what's the community/standard way of doing that?</p> <ul> <li>I know I could call mongo.Connect over and over again, but is that expensive?</li> <li>I could create different clients - each client with a different readpref - but I was thinking that if a write occurred on that connection, it wouldn't ever go back to reading from a slave.</li> <li>It looks like I *can create sessions explicitly, but I'm not certain I should or if there are any implications around managing those explicitly in the new driver.</li> </ul> </div>


<div class="post-text" itemprop="text"> <p>The update function of mongo-go-driver can be called like this.</p> <pre class="lang-golang prettyprint-override"><code>filter := bson.D{"username", username} update := bson.D{{"$set", bson.D{ {"name", person.Name}, }, }} result, err := collection.UpdateOne(ctx, filter, update) </code></pre> <pre class="lang-golang prettyprint-override"><code>type Person struct { ID primitive.ObjectID `json:"_id,omitempty" bson:"_id,omitempty"` Username string `json:"username,omitempty" bson:"username,omitempty"` Name string `json:"name,omitempty" bson:"name,omitempty"` } </code></pre> <p>But, I need to call the update function using the <code>person</code> struct, without mentioning every field of person struct like this.</p> <pre class="lang-golang prettyprint-override"><code>filter := bson.D{"username", username} update := bson.D{{"$set", &lt;&lt;how to convert person struct to bson document?&gt;&gt;}} result, err := collection.UpdateOne(ctx, filter, update) </code></pre> <p>How can I convert the person struct to bson document?</p> </div>


<div class="post-text" itemprop="text"> <p>I'm trying to do a full text search on a collection, but in order to do that I need to create a text index. How can I create a text index on two fields?</p> <p>I know that I must use a thing as this:</p> <pre><code>opts := options.CreateIndexes().SetMaxTime(10 * time.Second) idxFiles := []mongo.IndexModel{ { Keys: bsonx.Doc{{"name": "text"}}, }, } db.Collection("mycollection").Indexes().CreateMany(context, idx, opts) </code></pre> </div>


<div class="post-text" itemprop="text"> <p>I'm trying to find a document by its auto generated _id field. Code below returns nothing:</p> <pre><code>var documentID bson.RawValue documentID.Type = 7 documentID.Value = []byte("5c7452c7aeb4c97e0cdb75bf") objID := documentID.ObjectID() value := collection.FindOne(ctx, bson.M{"_id": objID}) </code></pre> <p>The value I provided is a real document id I got from Mongo Express </p> <pre><code>"_id": ObjectID("5c7452c7aeb4c97e0cdb75bf") </code></pre> <p>In case you're wondering why I bother with RawValue, I found examples using bson.EC.ObjectID but bson package doesn't seem to have EC type, also I found some examples mentioning github.com/mongodb/mongo-go-driver/bson/objectid package, but I could not find that package either. I previously developed with mgo but I'm new to mongo-go-driver, so if you can point an easy way to declare an ObjectID. </p> </div>


<div class="post-text" itemprop="text"> <p>So I am trying to use <a href="https://github.com/mongodb/mongo-go-driver" rel="nofollow noreferrer">https://github.com/mongodb/mongo-go-driver</a> to connect to a mongo database in golang.</p> <p>Here is my connection handler: </p> <pre><code>var DB *mongo.Database func CreateConnectionHandler()(*mongo.Database, error){ fmt.Println("inside createConnection in database package") godotenv.Load() fmt.Println("in CreateConnectionHandler and SERVER_CONFIG: ") fmt.Println(os.Getenv("SERVER_CONFIG")) uri:="" if os.Getenv("SERVER_CONFIG")=="kubernetes"{ fmt.Println("inside kubernetes db config") uri = "mongodb://patientplatypus:SUPERSECRETPASSDOOT@ mongo-release-mongodb.default.svc.cluster.local:27017/ platypusNEST?authMechanism=SCRAM-SHA-1" }else if os.Getenv("SERVER_CONFIG")=="compose"{ fmt.Println("inside compose db config") uri = "mongodb://datastore:27017" } ctx, _ := context.WithTimeout(context.Background(), 10*time.Second) client, err := mongo.Connect(ctx, uri) if err != nil { return nil, fmt.Errorf("mongo client couldn't connect: %v", err) } DB := client.Database("platypusNEST") return DB, nil } </code></pre> <p>And the error I am getting: </p> <pre><code>api | database/connection.go:29:30: cannot use uri (type string) as type *options.ClientOptions in argument to mongo.Connect </code></pre> <p>So I tried replacing <code>uri</code> with the connection string like this: </p> <pre><code>client, err := mongo.Connect(ctx, "mongodb://datastore:27017") </code></pre> <p>But I still got the error.</p> <p>Compare this with what is in the documentation: </p> <blockquote> <pre><code>ctx, _ := context.WithTimeout(context.Background(), 10*time.Second) client, err := mongo.Connect(ctx, "mongodb://localhost:27017") </code></pre> </blockquote> <p>And it is exactly the same! I'm really not sure why there is this error. Any ideas?</p> </div>


<div class="post-text" itemprop="text"> <p>I have a little problem with my Go service. I'm new to Go and I just want to dockerize a little service that just connect to a mongodb instance.</p> <p>My code works fine locally. So here is my Dockerfile:</p> <pre><code># build stage FROM golang:alpine AS build-env RUN apk add --no-cache git ADD . . RUN go get -v -u go.mongodb.org/mongo-driver RUN go build -o mongotest # final stage FROM alpine WORKDIR /app COPY --from=build-env ./go/mongotest . RUN apk update &amp;&amp; apk add ca-certificates &amp;&amp; rm -rf /var/cache/apk/* EXPOSE 8000 CMD ["./mongotest"] </code></pre> <p>When I build it, I have this error message :</p> <pre class="lang-none prettyprint-override"><code>Step 6/18 : RUN go get -v -u go.mongodb.org/mongo-driver ---&gt; Running in 4c45c601800d Fetching https://go.mongodb.org/mongo-driver?go-get=1 Parsing meta tags from https://go.mongodb.org/mongo-driver?go-get=1 (status code 200) get "go.mongodb.org/mongo-driver": found meta tag get.metaImport{Prefix:"go.mongodb.org/mongo-driver", VCS:"git", RepoRoot:"https://github.com/mongodb/mongo-go-driver.git"} at https://go.mongodb.org/mongo-driver?go-get=1 go.mongodb.org/mongo-driver (download) package go.mongodb.org/mongo-driver: no Go files in /go/src/go.mongodb.org/mongo-driver The command '/bin/sh -c go get -v -u go.mongodb.org/mongo-driver' returned a non-zero code: 1 </code></pre> <p><code>no Go files in /go/src</code> ... ok, what can I do with that?</p> <p>The strange thing is that if I replace </p> <p><code>RUN go get -d -u go.mongodb.org/mongo-driver</code></p> <p>by </p> <p><code>RUN go get -d -u github.com/gorilla/mux</code></p> <p>it works!</p> <p>Is there a problem with mongo driver repo?</p> </div>


<div class="post-text" itemprop="text"> <p>I'm trying to get a projection for the number of elements in a documents array.</p> <pre><code>options.SetProjection(bson.M{ "foo": true, "nrOfBars": bson.M{ "$size": "$bars" }, }) </code></pre> <p><code>bars</code> is the fieldname of the array.<br> This query though always returns 0 instead of the arrays length.</p> <p>How do I correctly query for the length of the array with the new mongo-go-driver?</p> </div>


<div class="post-text" itemprop="text"> <p>Hi there :) I'm working on a golang app linked to mongo DB (I use the official driver: <code>mongo-go</code>) and here's my problem,I want to execute this function </p> <pre><code>db.rmTickets.find().forEach(function(doc) { doc.created=new Date(doc.created) doc.updated=new Date(doc.updated) doc.deadline=new Date(doc.deadline) doc.dateEstimationDelivery=new Date(doc.dateEstimationDelivery) doc.dateTransmitDemand=new Date(doc.dateTransmitDemand) doc.dateTransmitQuotation=new Date(doc.dateTransmitQuotation) doc.dateValidationQuotation=new Date(doc.dateValidationQuotation) doc.dateDeliveryCS=new Date(doc.dateDeliveryCS) db.rmTickets.save(doc) }) </code></pre> <p>I see on godoc that a <code>Database.RunCommand()</code> exists but I'm not sure about how to use it. If someone can help :) Thanks </p> </div>


<div class="post-text" itemprop="text"> <p>I want create a dynamic filter with the mongo-go-driver.</p> <p>For example, I have this documents:</p> <pre><code>{ "_id":"5d1231380a2a2b39a99c3ed1"}, "name":"flower.png", "colors":["#ffffff","#212121","#999999","#dbdbdb","#ff5252"], }, { "_id":"5d1231380a2a2b39a99c3ed0"}, "name":"image of go.jpg", "colors":["#dedede","#dfdfdf","#dddddd","#e0e0e0","#e2e2e2"], }, { "_id":"5d1231380a2a2b39a99c3ecf"}, "name":"bolket rulez.png", "colors":["#000000","#010101","#020202","#030303","#040404"], }, { "_id":"5d1231380a2a2b39a99c3ecf"}, "name":"bolket photo.png", "colors":["#ffffff","#010101","#020202","#030303","#040404"], } </code></pre> <p>Now I want all documents that have "bolket" in the name and "#ffffff" color.</p> <p>I have tryed with this filter:</p> <pre><code>filter := make(bson.D, 2) if f.Name != "" { filter = append(filter, bson.E{Key: "name", Value: bson.M{"$text": bson.M{"$search": f.Name}}}) } if f.Color != "" { filter = append(filter, bson.E{Key: "colors", Value: bson.M{"$in": f.Color}}) } </code></pre> <p>But with this filter I have this error: <code>(BadValue) unknown operator: $text </code></p> <p>How can I create a dynamic filter???</p> </div>


<div class="post-text" itemprop="text"> <p>I am very new to both Go and Mongodb and was writing my first rest-api with Go and Mongo. I am using <code>mongo-go-driver</code> and have the following <code>Modal</code> struct in Go </p> <pre><code>type Modal struct { Group []string `bson:"group" json:"group"` Hostname string `bson:"hostname" json:"hostname"` Overrides map[string]string `bson:"overrides" json:"overrides"` Excludes []string `bson:"excludes" json:"excludes"` } </code></pre> <p>I do not want to use the default <code>ObjectId</code> field provided by mongo-db as my primary key and instead would like to make the <code>Hostname</code> field as the primary key.</p> <p>If I make the type of <code>Hostname</code> field as <code>primitive.ObjectID</code>, then the <code>hostname</code> would be unique but its value will be randomly generated string by mongodb and not the actual hostname string value.</p> <p>So is there a way I can do this.</p> </div>

官方mongo-go-driver的UpdateOne中$ set的bson语法是什么

<div class="post-text" itemprop="text"> <p>I am trying to get some familiarity with the official <a href="https://godoc.org/go.mongodb.org/mongo-driver/mongo" rel="nofollow noreferrer">mongo-go-driver</a> and ran into an hour-long delay trying to figure out the right syntax for <code>UpdateOne</code>. </p> <p>My simplest full example follows (NOTE: in order to use this code you will need to substitute in your own user and server names as well as export the login password to the environment as MONGO_PW):</p> <pre class="lang-golang prettyprint-override"><code>package main import ( "context" "fmt" "os" "go.mongodb.org/mongo-driver/bson" "go.mongodb.org/mongo-driver/bson/primitive" "go.mongodb.org/mongo-driver/mongo" "go.mongodb.org/mongo-driver/mongo/options" ) type DB struct { User string Server string Database string Collection string Client *mongo.Client Ctx context.Context } var db = DB{ User: &lt;username&gt;, Server: &lt;server_IP&gt;, Database: "test", Collection: "movies", Ctx: context.TODO(), } type Movie struct { ID primitive.ObjectID `bson:"_id" json:"id"` Name string `bson:"name" json:"name"` Description string `bson:"description" json:"description"` } func main() { if err := db.Connect(); err != nil { fmt.Println("error: unable to connect") os.Exit(1) } fmt.Println("connected") // The code assumes the original entry for dunkirk is the following // {"Name":"dunkirk", "Description":"a world war 2 movie"} updatedMovie := Movie{ Name: "dunkirk", Description: "movie about the british evacuation in WWII", } res, err := db.UpdateByName(updatedMovie) if err != nil { fmt.Println("error updating movie:", err) os.Exit(1) } if res.MatchedCount &lt; 1 { fmt.Println("error: update did not match any documents") os.Exit(1) } } // UpdateByName changes the description for a movie identified by its name func (db *DB) UpdateByName(movie Movie) (*mongo.UpdateResult, error) { filter := bson.D{{"name", movie.Name}} res, err := db.Client.Database(db.Database).Collection(db.Collection).UpdateOne( db.Ctx, filter, movie, ) if err != nil { return nil, err } return res, nil } // Connect assumes that the database password is stored in the // environment variable MONGO_PW func (db *DB) Connect() error { pw, ok := os.LookupEnv("MONGO_PW") if !ok { fmt.Println("error: unable to find MONGO_PW in the environment") os.Exit(1) } mongoURI := fmt.Sprintf("mongodb+srv://%s:%s@%s", db.User, pw, db.Server) // Set client options and verify connection clientOptions := options.Client().ApplyURI(mongoURI) client, err := mongo.Connect(db.Ctx, clientOptions) if err != nil { return err } err = client.Ping(db.Ctx, nil) if err != nil { return err } db.Client = client return nil } </code></pre> <p>The function signature for <code>UpdateOne</code> from the package docs is:</p> <pre class="lang-golang prettyprint-override"><code>func (coll *Collection) UpdateOne(ctx context.Context, filter interface{}, update interface{}, opts ...*options.UpdateOptions) (*UpdateResult, error) </code></pre> <p>So I am clearly making some sort of mistake in creating the <code>update interface{}</code> argument to the function because I am presented with this error</p> <pre class="lang-none prettyprint-override"><code>error updating movie: update document must contain key beginning with '$' </code></pre> <p>The most popular answer <a href="https://stackoverflow.com/questions/38883285/error-the-update-operation-document-must-contain-atomic-operators-when-running">here</a> shows that I need to use a document sort of like this </p> <pre><code>{ $set: {"Name" : "The Matrix", "Decription" "Neo and Trinity kick butt" } } </code></pre> <p>but taken verbatim this will not compile in the mongo-go-driver.</p> <p>I think I need some form of a bson document to comply with the Go syntax. What is the best and/or most efficient syntax to create this bson document for the <code>update</code>?</p> </div>


<div class="post-text" itemprop="text"> <p>I am using the package: <code>"github.com/mongodb/mongo-go-driver/mongo"</code></p> <p>I am trying to use the following as specified in the <a href="https://godoc.org/github.com/mongodb/mongo-go-driver/mongo" rel="nofollow noreferrer">documentation</a>:</p> <pre><code>mongoContext, _ := context.WithTimeout(context.Background(), 10*time.Second) mongoClient, _ := mongo.Connect(mongoContext, "mongodb://localhost:27017") </code></pre> <p>However on the second line I get the error:</p> <pre><code>cannot use "mongodb://localhost:27017" (type string) as type *options.ClientOptions in argument to mongo.Connect </code></pre> <p>It seems the documentation doesn't match the implementation. Has anyone been successful?</p> <p><strong>The documentation states:</strong></p> <pre><code>//To do this in a single step, you can use the Connect function: ctx, _ := context.WithTimeout(context.Background(), 10*time.Second) client, err := mongo.Connect(ctx, "mongodb://localhost:27017") </code></pre> </div>


<div class="post-text" itemprop="text"> <p>I want to convert bson in <a href="https://github.com/mongodb/mongo-go-driver" rel="nofollow noreferrer">mongo-go-driver</a> to json effectively.</p> <p>I should take care to handle <code>NaN</code>, because <code>json.Marshal</code> fail if <code>NaN</code> exists in data.</p> <p>For instance, I want to convert below bson data to json.</p> <pre class="lang-golang prettyprint-override"><code>b, _ := bson.Marshal(bson.M{"a": []interface{}{math.NaN(), 0, 1}}) // How to convert b to json? </code></pre> <p>The below fails.</p> <pre class="lang-golang prettyprint-override"><code>// decode var decodedBson bson.M bson.Unmarshal(b, &amp;decodedBson) _, err := json.Marshal(decodedBson) if err != nil { panic(err) // it will be invoked // panic: json: unsupported value: NaN } </code></pre> </div>


<div class="post-text" itemprop="text"> <p>FindOneAndReplace may or may not replace the document in MongoDB. The response indicates that the operation succeeded, but looking into MongoDB it was not updated at all.</p> <p>The MongoDB server version is MongoDB server version: 3.2.0 This bug is reproducible in Ubuntu 16.04 and macOS Mojave. The target host is Azure CosmosDB.</p> <p>The driver version is mongo-go-driver@v0.0.17</p> <pre><code>func (s *Service) DeleteFileMetadata(ctx context.Context, req *pb.DocumentRequest) (*pb.DocumentResponse, error) { log.Println("[INFO] Requesting DeleteFileMetadata service") if ok := isStateAvailable(); !ok { log.Printf("[ERROR] %s ", errServiceUnavailable.Error()) return nil, status.Error(codes.Unavailable, errServiceUnavailable.Error()) } if err := refreshMongoDBConnection(mongoDBWriter, &amp;conf.DocumentDB.Writer); err != nil { log.Printf("[ERROR] %s ", err.Error()) return nil, status.Error(codes.Internal, err.Error()) } if req == nil { log.Printf("[ERROR] %s ", errNilRequest.Error()) return nil, status.Error(codes.InvalidArgument, errNilRequest.Error()) } fileMetadataParameters := req.GetFileMetadataParameters() if fileMetadataParameters == nil || fileMetadataParameters.GetDuid() == "" { log.Printf("[ERROR] %s ", errInvalidFileMetadataParameters.Error()) return nil, status.Error(codes.InvalidArgument, errInvalidFileMetadataParameters.Error()) } if err := ValidateDUID(fileMetadataParameters.GetDuid()); err != nil { log.Printf("[ERROR] %s ", err.Error()) return nil, status.Error(codes.InvalidArgument, err.Error()) } if err := ValidateUUID(fileMetadataParameters.GetUuid()); err != nil { log.Printf("[ERROR] %s ", err.Error()) return nil, status.Error(codes.InvalidArgument, err.Error()) } if err := ValidateFUID(fileMetadataParameters.GetFuid()); err != nil { log.Printf("[ERROR] %s ", err.Error()) return nil, status.Error(codes.InvalidArgument, err.Error()) } if fileMetadataParameters.Media &gt; pb.FileType_VIDEO { return nil, status.Error(codes.InvalidArgument, errMediaType.Error()) } log.Printf("[INFO] FileMetadataParameters: %v ", pretty.Sprint(req.GetFileMetadataParameters())) // Get the specific lock if it already exists, else make the lock lock, _ := duidClientLocker.LoadOrStore(fileMetadataParameters.GetDuid(), &amp;sync.RWMutex{}) // Lock lock.(*sync.RWMutex).Lock() // Unlock before the function exits defer lock.(*sync.RWMutex).Unlock() collection := mongoDBWriter.Database(conf.DocumentDB.Name).Collection(conf.DocumentDB.Collection) // Find all MongoDB documents for the specific uuid filter := bson.NewDocument( bson.EC.String("duid", fileMetadataParameters.GetDuid()), bson.EC.String("uuid", fileMetadataParameters.GetUuid()), ) bsonResult := collection.FindOne(context.Background(), filter) if bsonResult == nil { log.Printf("[ERROR] FindOne: %s ", errNoDocumentFound.Error()) return nil, status.Error(codes.InvalidArgument, errNoDocumentFound.Error()) } documentToUpdate := &amp;pb.Document{} if err := bsonResult.Decode(documentToUpdate); err != nil { log.Printf("[ERROR] Document not found, duid: %s - uuid: %s - err: %s ", fileMetadataParameters.GetDuid(), fileMetadataParameters.GetUuid(), err.Error()) return nil, status.Errorf(codes.InvalidArgument, "Document not found, duid: %s - uuid: %s", fileMetadataParameters.GetDuid(), fileMetadataParameters.GetUuid()) } log.Printf("[INFO] Document to update: %s ", pretty.Sprint(documentToUpdate)) switch fileMetadataParameters.Media { case pb.FileType_FILE: delete(documentToUpdate.GetFileUrlsMap(), fileMetadataParameters.GetFuid()) case pb.FileType_AUDIO: delete(documentToUpdate.GetAudioUrlsMap(), fileMetadataParameters.GetFuid()) case pb.FileType_IMAGE: delete(documentToUpdate.GetImageUrlsMap(), fileMetadataParameters.GetFuid()) case pb.FileType_VIDEO: delete(documentToUpdate.GetVideoUrlsMap(), fileMetadataParameters.GetFuid()) default: return nil, status.Error(codes.InvalidArgument, errMediaType.Error()) } documentToUpdate.UpdateTimestamp = time.Now().UTC().Unix() // option to return the the document after update option := findopt.ReplaceOneBundle{} result := collection.FindOneAndReplace(context.Background(), filter, documentToUpdate, option.ReturnDocument(mongoopt.After)) // Extract the updated MongoDB document if result == nil { log.Printf("[ERROR] Extracting updated document, duid: %s - uuid: %s ", documentToUpdate.GetDuid(), documentToUpdate.GetUuid()) return nil, status.Errorf(codes.Internal, "Extracting updated document duid: %s - uuid: %s", documentToUpdate.GetDuid(), documentToUpdate.GetUuid()) } document := &amp;pb.Document{} if err := result.Decode(document); err != nil { log.Printf("[ERROR] %s ", err.Error()) return nil, status.Errorf(codes.Internal, err.Error()) } log.Printf("[INFO] Updated document: %s ", pretty.Sprint(document)) log.Printf("[INFO] Success deleting file metadata in document, duid: %s - uuid: %s - fuid: %s ", document.GetDuid(), document.GetUuid(), fileMetadataParameters.GetFuid()) return &amp;pb.DocumentResponse{ Status: &amp;pb.DocumentResponse_Code{Code: uint32(codes.OK)}, Message: codes.OK.String(), Data: document, }, nil } </code></pre> <p>I expect that response reflects the actual state of the data in the MongoDB server.</p> <p>Let us say I want to delete a filemetadata with fuid of <code>05ce38e7-a29a-485f-bf20-eef3501867f0</code></p> <p>I get this response indicating that it was deleted. The response was decoded from <code>result := collection.FindOneAndReplace(context.Background(), filter, documentToUpdate, option.ReturnDocument(mongoopt.After))</code></p> <pre><code> ImageUrlsMap: {217706a5-2f88-4eb2-8a93-c1426c5ac944: "https://hwscdevstorage.blob.core.windows.net/images/hulkgif.png", 4ff30392-8ec8-45a4-ba94-5e22c4a686df: "https://hwscdevstorage.blob.core.windows.net/images/Rotating_earth_(large).gif"}, AudioUrlsMap: {4ff30392-8ec8-45a4-ba94-5e22c4a686df: "https://hwscdevstorage.blob.core.windows.net/audios/Milad Hosseini - Deli Asheghetam [128].mp3", 8fe5fea7-f683-4198-8c94-f27601a5e2d0: "https://hwscdevstorage.blob.core.windows.net/audios/Seger_Conga_CaboMexico_Tag_Acousonde_20140313_112313_8000_3_BreedingMigrating.wav"}, VideoUrlsMap: {4ff30392-8ec8-45a4-ba94-5e22c4a686de: "https://hwscdevstorage.blob.core.windows.net/videos/videoplayback.wmv", 4ff30392-8ec8-45a4-ba94-5e22c4a686df: "https://hwscdevstorage.blob.core.windows.net/videos/videoplayback.mp4", e525ca9c-9813-4286-abda-8bd0eb6e94b4: "https://hwscdevstorage.blob.core.windows.net/videos/pusheen.mp4"}, FileUrlsMap: {13df1afa-4eee-470e-b9e2-60b2a7584994: "https://hwscdevstorage.blob.core.windows.net/videos/videoplayback.wmv", 4ff30392-8ec8-45a4-ba94-5e22c4a686df: "https://hwscdevstorage.blob.core.windows.net/videos/videoplayback.mp4", b7a16e10-ac03-468f-9b6d-dcc684d1147f: "https://hwscdevstorage.blob.core.windows.net/videos/pusheen.mp4"}, RecordTimestamp: 1514764800, CreateTimestamp: 1539831496, UpdateTimestamp: 1546183549, IsPublic: true, XXX_NoUnkeyedLiteral: {}, XXX_unrecognized: [], XXX_sizecache: 0} 2018/12/30 07:25:49 [INFO] Success deleting file metadata in document, duid: 1ChHfmKs8GX7D1XVf61lwVdisWf - uuid: 0XXXXSNJG0MQJHBF4QX1EFD6Y3 - fuid: 05ce38e7-a29a-485f-bf20-eef3501867f0 </code></pre> <p>But if I go to Azure CosmosDB or in my local server, it is still there. <a href="https://i.stack.imgur.com/dfknK.png" rel="nofollow noreferrer">screenshot</a></p> </div>


<div class="post-text" itemprop="text"> <p>How can I filter fields with the mongo-go-driver. Tried it with findopt.Projection but no success. </p> <pre><code>type fields struct { _id int16 } s := bson.NewDocument() filter := bson.NewDocument(bson.EC.ObjectID("_id", starterId)) var opts []findopt.One opts = append(opts, findopt.Projection(fields{ _id: 0, })) staCon.collection.FindOne(nil, filter, opts...).Decode(s) </code></pre> <p>In the end, I want to suppress the field "_id". But the documents didn't change.</p> </div>


<div class="post-text" itemprop="text"> <p>I'm trying to do an aggregation with mongo-go-driver (MongoDB team driver for Golang) and I can't see what I'm doing wrong here: </p> <pre><code>// group group, e := bson.ParseExtJSONObject(` { "$group": { "_id":{ "ProductCode":"$ProductCode", "Dir":"$Dir", "WharehouseID":"$WharehouseID" } } } `) cursor, e := myCollection.Aggregate( context.Background(), group, ) // e output: "(Location40324) Unrecognized pipeline stage name: '_id'" </code></pre> <p>This is a mongodb error but if I execute this query in a mongodb native client I get the results and no error occurs. </p> </div>

使用MongoDB Atlas时,mongo-go-driver失败,服务器选择超时

<div class="post-text" itemprop="text"> <p>Go Version: 1.12.5</p> <p>I have this code which uses the node.js mongo driver</p> <pre><code>const MongoClient = require('mongodb').MongoClient; const uri = process.env.MONGO_HOST + "dbname?retryWrites=true"; const client = new MongoClient(uri, { useNewUrlParser: true }); client.connect(async (err) =&gt; { if (err) { throw err } const collection = client.db("dbname").collection("collectionName"); const cursor = collection.find() await cursor.forEach(console.log) // perform actions on the collection object client.close(); }); </code></pre> <p>Which works fine.</p> <p>Using the <code>mongo-go-driver</code>, I do:</p> <pre><code>client, err := mongo.NewClient(options.Client().ApplyURI(os.Getenv("MONGO_HOST") + "dbname?retryWrites=true") if err != nil { panic(err) } ctx, _ := context.WithTimeout(context.Background(), 10*time.Second) err = client.Connect(ctx) if err != nil { panic(err) } database := client.Database("dbname") collection := database.Collection("collectionName") res, err := collection.Find(context.Background(), bson.M{}, &amp;options.FindOptions{ Sort: bson.M{ "priority": -1, }, }) if err != nil { panic(err) } results := make([]structs.ResponseType, 0) err = res.All(context.Background(), &amp;results) if err != nil { panic(err) } </code></pre> <p>But this panics with:</p> <pre><code>panic: server selection error: server selection timeout current topology: Type: ReplicaSetNoPrimary </code></pre> <p>I am not running this inside a container/docker.</p> </div>

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想学好JAVA必须要报两万的培训班吗? Java大神勿入 如果你: 零基础想学JAVA却不知道从何入手 看了一堆书和视频却还是连JAVA的环境都搭建不起来 囊中羞涩面对两万起的JAVA培训班不忍直视 在职没有每天大块的时间专门学习JAVA 那么恭喜你找到组织了,在这里有: 1. 一群志同道合立志学好JAVA的同学一起学习讨论JAVA 2. 灵活机动的学习时间完成特定学习任务+每日编程实战练习 3. 热心助人的助教和讲师及时帮你解决问题,不按时完成作业小心助教老师的家访哦 上一张图看看前辈的感悟: &nbsp; &nbsp; 大家一定迫不及待想知道什么是极简JAVA学习营了吧,下面就来给大家说道说道: 什么是极简JAVA学习营? 1. 针对Java小白或者初级Java学习者; 2. 利用9天时间,每天1个小时时间; 3.通过 每日作业 / 组队PK / 助教答疑 / 实战编程 / 项目答辩 / 社群讨论 / 趣味知识抢答等方式让学员爱上学习编程 , 最终实现能独立开发一个基于控制台的‘库存管理系统’ 的学习模式 极简JAVA学习营是怎么学习的? &nbsp; 如何报名? 只要购买了极简JAVA一:JAVA入门就算报名成功! &nbsp;本期为第四期极简JAVA学习营,我们来看看往期学员的学习状态: 作业看这里~ &nbsp; 助教的作业报告是不是很专业 不交作业打屁屁 助教答疑是不是很用心 &nbsp; 有奖抢答大家玩的很嗨啊 &nbsp; &nbsp; 项目答辩终于开始啦 &nbsp; 优秀者的获奖感言 &nbsp; 这是答辩项目的效果 &nbsp; &nbsp; 这么细致的服务,这么好的氛围,这样的学习效果,需要多少钱呢? 不要1999,不要199,不要99,只要9.9 是的你没听错,只要9.9以上所有就都属于你了 如果你: 1、&nbsp;想学JAVA没有基础 2、&nbsp;想学JAVA没有整块的时间 3、&nbsp;想学JAVA没有足够的预算 还等什么?赶紧报名吧,抓紧抢位,本期只招300人,错过只有等时间待定的下一期了 &nbsp; 报名请加小助手微信:eduxy-1 &nbsp; &nbsp;


董付国系列教材《Python程序设计基础》、《Python程序设计(第2版)》、《Python可以这样学》配套视频,讲解Python 3.5.x和3.6.x语法、内置对象用法、选择与循环以及函数设计与使用、lambda表达式用法、字符串与正则表达式应用、面向对象编程、文本文件与二进制文件操作、目录操作与系统运维、异常处理结构。


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机器学习实战系列套餐以实战为出发点,帮助同学们快速掌握机器学习领域必备经典算法原理并结合Python工具包进行实战应用。建议学习顺序:1.Python必备工具包:掌握实战工具 2.机器学习算法与实战应用:数学原理与应用方法都是必备技能 3.数据挖掘实战:通过真实数据集进行项目实战。按照下列课程顺序学习即可! 课程风格通俗易懂,用最接地气的方式带领大家轻松进军机器学习!提供所有课程代码,PPT与实战数据,有任何问题欢迎随时与我讨论。


发现网上很多Java面试题都没有答案,所以花了很长时间搜集整理出来了这套Java面试题大全,希望对大家有帮助哈~ 本套Java面试题大全,全的不能再全,哈哈~ 一、Java 基础 1. JDK 和 JRE 有什么区别? JDK:Java Development Kit 的简称,java 开发工具包,提供了 java 的开发环境和运行环境。 JRE:Java Runtime Environ...


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本课程为HoloLens2开发入门教程,讲解部署开发环境,安装VS2019,Unity版本,Windows SDK,创建Unity项目,讲解如何使用MRTK,编辑器模拟手势交互,打包VS工程并编译部署应用到HoloLens上等。


本文的面试题如下: Redis 持久化机制 缓存雪崩、缓存穿透、缓存预热、缓存更新、缓存降级等问题 热点数据和冷数据是什么 Memcache与Redis的区别都有哪些? 单线程的redis为什么这么快 redis的数据类型,以及每种数据类型的使用场景,Redis 内部结构 redis的过期策略以及内存淘汰机制【~】 Redis 为什么是单线程的,优点 如何解决redis的并发竞争key问题 Red...



【数据结构与算法综合实验】欢乐连连看(C++ & MFC)案例

这是武汉理工大学计算机学院数据结构与算法综合实验课程的第三次项目:欢乐连连看(C++ & MFC)迭代开发代码。运行环境:VS2017。已经实现功能:开始游戏、消子、判断胜负、提示、重排、计时、帮助。


YOLOv3是一种基于深度学习的端到端实时目标检测方法,以速度快见长。本课程将手把手地教大家使用labelImg标注和使用YOLOv3训练自己的数据集。课程分为三个小项目:足球目标检测(单目标检测)、梅西目标检测(单目标检测)、足球和梅西同时目标检测(两目标检测)。 本课程的YOLOv3使用Darknet,在Ubuntu系统上做项目演示。包括:安装Darknet、给自己的数据集打标签、整理自己的数据集、修改配置文件、训练自己的数据集、测试训练出的网络模型、性能统计(mAP计算和画出PR曲线)和先验框聚类。 Darknet是使用C语言实现的轻型开源深度学习框架,依赖少,可移植性好,值得深入探究。 除本课程《YOLOv3目标检测实战:训练自己的数据集》外,本人推出了有关YOLOv3目标检测的系列课程,请持续关注该系列的其它课程视频,包括: 《YOLOv3目标检测实战:交通标志识别》 《YOLOv3目标检测:原理与源码解析》 《YOLOv3目标检测:网络模型改进方法》 敬请关注并选择学习!



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