利用golang驱动操作MongoDB数据库的步骤

mkdr mongodb 
cd mongodb 
go mod init 
go get go.mongodb.org/mongo-driver/mongo

package main

import (
 "context"
 "fmt"
 "log"
 "go.mongodb.org/mongo-driver/bson"
 "go.mongodb.org/mongo-driver/mongo"
 "go.mongodb.org/mongo-driver/mongo/options"
 "time"
)

mongodb://[username:password@]host1[:port1][,...hostN[:portN]][/[defaultauthdb][?options]]

mongodb://localhost:27017

mongodb://mongodb0.example.com:27017,mongodb1.example.com：27017，mongodb2.example.com：27017 /?replicaSet = myRepl

mongodb://mongos0.example.com:27017,mongos1.example.com:27017,mongos2.example.com:27017

func main() {
 clientOptions := options.Client().ApplyURI("mongodb://admin:password@localhost:27017")
 var ctx = context.TODO()
 // Connect to MongoDB
 client, err := mongo.Connect(ctx, clientOptions)
 if err != nil {
 log.Fatal(err)
 }
 // Check the connection
 err = client.Ping(ctx, nil)
 if err != nil {
 log.Fatal(err)
 }
 fmt.Println("Connected to MongoDB!")
 defer client.Disconnect(ctx)

databases, err := client.ListDatabaseNames(ctx, bson.M{})
if err != nil {
 log.Fatal(err)
}
fmt.Println(databases)

//定义插入数据的结构体
type sunshareboy struct {
Name string
Age int
City string
}
//连接到test库的sunshare集合,集合不存在会自动创建
collection := client.Database("test").Collection("sunshare")
wanger:=sunshareboy{"wanger",24,"北京"}
insertOne,err :=collection.InsertOne(ctx,wanger)
if err != nil {
log.Fatal(err)
}
fmt.Println("Inserted a Single Document: ", insertOne.InsertedID)

var result sunshareboy
filter := bson.D{{"name","wanger"}}
err = collection.FindOne(context.TODO(), filter).Decode(&result)
if err != nil {
 log.Fatal(err)
}
fmt.Printf("Found a single document: %+v\n", result)

//定义返回文档数量
findOptions := options.Find()
findOptions.SetLimit(5)

//定义一个切片存储结果
var results []*sunshareboy

//将bson.D{{}}作为一个filter来匹配所有文档
cur, err := collection.Find(context.TODO(), bson.D{{}}, findOptions)
if err != nil {
 log.Fatal(err)
}
//查找多个文档返回一个游标
//遍历游标一次解码一个游标
for cur.Next(context.TODO()) {
 //定义一个文档，将单个文档解码为result
 var result sunshareboy
 err := cur.Decode(&result)
 if err != nil {
  log.Fatal(err)
 }
 results = append(results, &result)
}
fmt.Println(result)
if err := cur.Err(); err != nil {
 log.Fatal(err)
}
//遍历结束后关闭游标
cur.Close(context.TODO())
fmt.Printf("Found multiple documents (array of pointers): %+v\n", results)

filter := bson.D{{"name","张冬冬"}}
//如果过滤的文档不存在，则插入新的文档
opts := options.Update().SetUpsert(true)
update := bson.D{
{"$set", bson.D{
 {"city", "北京"}},
}}
result, err := collection.UpdateOne(context.TODO(), filter, update,opts)
if err != nil {
log.Fatal(err)
}
if result.MatchedCount != 0 {
fmt.Printf("Matched %v documents and updated %v documents.\n", result.MatchedCount, result.ModifiedCount)
}
if result.UpsertedCount != 0 {
fmt.Printf("inserted a new document with ID %v\n", result.UpsertedID)
}

filter := bson.D{{"city","北京"}}
//如果过滤的文档不存在，则插入新的文档
opts := options.Update().SetUpsert(true)
update := bson.D{
{"$set", bson.D{
 {"city", "铁岭"}},
}}
result, err := collection.UpdateMany(context.TODO(), filter, update,opts)
if err != nil {
log.Fatal(err)
}
if result.MatchedCount != 0 {
fmt.Printf("Matched %v documents and updated %v documents.\n", result.MatchedCount, result.ModifiedCount)
}
if result.UpsertedCount != 0 {
fmt.Printf("inserted a new document with ID %v\n", result.UpsertedID)
}

filter := bson.D{{"city","铁岭"}}
deleteResult, err := collection.DeleteMany(context.TODO(), filter)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Deleted %v documents in the trainers collection\n", deleteResult.DeletedCount)

ctx, _ = context.WithTimeout(context.Background(), 30*time.Second)
serverStatus, err := client.Database("admin").RunCommand(
ctx,
bsonx.Doc{{"serverStatus", bsonx.Int32(1)}},
).DecodeBytes()
if err != nil {
fmt.Println(err)
}
fmt.Println(serverStatus)
fmt.Println(reflect.TypeOf(serverStatus))
version, err := serverStatus.LookupErr("version")
fmt.Println(version.StringValue())
if err != nil {
fmt.Println(err)
}