安装MongoDB驱动程序
mkdr mongodb
cd mongodb
go mod init
go get go.mongodb.org/mongo-driver/mongo连接MongoDB
创建一个main.go文件
将以下包导入main.go文件中
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"
)连接MongoDB的URI格式为
mongodb://[username:password@]host1[:port1][,...hostN[:portN]][/[defaultauthdb][?options]]单机版
mongodb://localhost:27017副本集
mongodb://mongodb0.example.com:27017,mongodb1.example.com：27017，mongodb2.example.com：27017 /?replicaSet = myRepl分片集群
mongodb://mongos0.example.com:27017,mongos1.example.com:27017,mongos2.example.com:27017context.TODO()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)列出所有数据库
databases, err := client.ListDatabaseNames(ctx, bson.M{})
if err != nil {
log.Fatal(err)
}
fmt.Println(databases)在GO中使用BSON对象
Raw系列D//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)
执行结果如下
#### 同时插入多条文档
```go
collection := client.Database("test").Collection("sunshare")
dongdong:=sunshareboy{"张冬冬",29,"成都"}
huazai:=sunshareboy{"华仔",28,"深圳"}
suxin:=sunshareboy{"素心",24,"甘肃"}
god:=sunshareboy{"刘大仙",24,"杭州"}
qiaoke:=sunshareboy{"乔克",29,"重庆"}
jiang:=sunshareboy{"姜总",24,"上海"}
//插入多条数据要用到切片
boys:=[]interface{}{dongdong,huazai,suxin,god,qiaoke,jiang}
insertMany,err:= collection.InsertMany(ctx,boys)
if err != nil {
log.Fatal(err)
}
fmt.Println("Inserted multiple documents: ", insertMany.InsertedIDs)从MongDB中查询数据
查询单个文档
查询单个文档使用collection.FindOne()函数，需要一个filter文档和一个可以将结果解码为其值的指针
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)返回结果如下
Connected to MongoDB!
Found a single document: {Name:wanger Age:24 City:北京}
Connection to MongoDB closed.查询多个文档
查询多个文档使用collection.Find()函数，这个函数会返回一个游标，可以通过他来迭代并解码文档，当迭代完成后，关闭游标
//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)返回结果如下
Connected to MongoDB!
{wanger 24 北京}
{张冬冬 29 成都}
{华仔 28 深圳}
{素心 24 甘肃}
{刘大仙 24 杭州}
Found multiple documents (array of pointers): &[0xc000266450 0xc000266510 0xc000266570 0xc0002665d0 0xc000266630]
Connection to MongoDB closed.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{
{"$set", bson.D{
{"city", "北京"}},
}}
result, err := collection.UpdateOne(context.TODO(), filter, update,opts)
if err != nil {
log.Fatal(err)
}
if result.MatchedCount != 0 {
fmt.Printf("Matched %v documents and updated %v documents.\n", result.MatchedCount, result.ModifiedCount)
}
if result.UpsertedCount != 0 {
fmt.Printf("inserted a new document with ID %v\n", result.UpsertedID)
}返回结果如下
Connected to MongoDB!
Matched 1 documents and updated 1 documents.
Connection to MongoDB closed.更新多个文档
更新多个文档使用collection.UpdateOne()函数，参数与collection.UpdateOne()函数相同
filter := bson.D{{"city","北京"}}
//如果过滤的文档不存在，则插入新的文档
opts := options.Update().SetUpsert(true)
update := bson.D{
{"$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)
}返回结果如下
Connected to MongoDB!
Matched 2 documents and updated 2 documents.
Connection to MongoDB closed.删除MongoDB文档
collection.DeleteOne()collection.DeleteMany()bson.D{{}}collection. drop()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)返回结果如下
Connected to MongoDB!
Deleted 2 documents in the trainers collection
Connection to MongoDB closed.获取MongoDB服务状态
上面我们介绍了对MongoDB的CRUD，其实还支持很多对mongoDB的操作，例如聚合、事物等，接下来介绍一下使用golang获取MongoDB服务状态，执行后会返回一个bson.Raw类型的数据
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)
}参考链接
https://www.mongodb.com/blog/post/mongodb-go-driver-tutorial
https://godoc.org/go.mongodb.org/mongo-driver/mongo