MongoDB Go Driver基本用法小结

mongoDB的官方golang支持库,尚处于测试阶段。

以下为示例代码分析总结,实现最基本的CRUD操作,

可供初学者学习参考和引用。

注意:源码并不能直接运行!

本文首发于个人博客MongoDB Go Driver用法小结

安装

推荐使用goland与go mod(go modules )

官方网站:mongo-go-driver, go modules.

在需要用到的项目中任意一个包import链接,然后右键进行sync操作,便可以导入包,注意设置代理

//example
...
import (
 "go.mongodb.org/mongo-driver/mongo"
 "go.mongodb.org/mongo-driver/mongo/options"
)
...

初始化

在本地数据库环境下进行,所以请确保已经开启本地的数据库服务,可通过终端运行mongo命令进行判断。

var ctx = context.Background() // create a new context
var UserColl *mongo.Collection // create a new collection
type User struct { // user type for example
 ID primitive.ObjectID `bson:"_id"`
 Username string `bson:"username" `
 Psw string `bson:"password" `
 CreatedAt time.Time `bson:"created_at"`
 UpdatedAt time.Time `bson:"updated_at"`
}
// connect database
func init() {
 ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
 client, err := mongo.Connect(ctx, options.Client().ApplyURI("mongodb://localhost:27017")) // change the URI when you need
 if err != nil {
 log.Fatal(err)
 }
 // check connection
 ctx, _ = context.WithTimeout(context.Background(), 2*time.Second)
 if err = client.Ping(ctx, readpref.Primary()); err != nil {
 log.Fatal(err)
 }
 //example coll
 UserColl = client.Database("[db name]").Collection("[coll name]")
}

增

单个新增

// controllers
func ExampleMongo() {
 // insert one user
 NewUser := User{
 Username: "userA",
 Psw: "123",
 }
 if res, err := InsertOneUser(NewUser); err != nil {
 return
 } else {
 fmt.Println("new post created with id: %s", res.InsertedID.(primitive.ObjectID).Hex())
 }
}
 
// models
func InsertOneUser(user User) (*mongo.InsertOneResult, error) {
 res, err := UserColl.InsertOne(ctx, bson.M{
 "username": user.Username,
 "psw": user.Psw,
 "created_at": time.Now(),
 "updated_at": time.Now()})
 return res, err
}

多个新增

// controllers
func ExampleMongo() {
 // insert many users
 NewUsers := make([]User, 1)
 NewUsers = append(NewUsers, User{
 Username: "userB",
 Psw: "123",
 }, User{
 Username: "userC",
 Psw: "123",
 })
 if res, err := InsertManyUsers(NewUsers); err != nil {
 return
 } else {
 fmt.Printf("inserted ids: %v\n", res.InsertedIDs)
 }
}
// models
func InsertManyUsers(users []User) (*mongo.InsertManyResult, error) {
 res, err := UserColl.InsertMany(ctx, []interface{}{
 bson.M{
 "username": users[1].Username,
 "psw": users[1].Psw,
 "created_at": time.Now(),
 "updated_at": time.Now()},
 bson.M{
 "username": users[2].Username,
 "psw": users[2].Psw,
 "created_at": time.Now(),
 "updated_at": time.Now()}})
 return res, err
}

删

单个删除

// controllers
func ExampleMongo() {
 // delete one user
 // you can design your own filter
 id, err := primitive.ObjectIDFromHex("[user id]")
 if err != nil {
 return
 }
 filterDeleteOne := bson.M{"_id": id}
 if res, err := DeleteOneUser(filterDeleteOne); err != nil {
 return
 } else {
 fmt.Printf("deleted count: %d\n", res.DeletedCount)
 }
}
// models
func DeleteOneUser(filter bson.M) (*mongo.DeleteResult, error) {
 res, err := UserColl.DeleteOne(ctx, filter)
 return res, err
}

多个删除

// controllers
func ExampleMongo() {
 // delete many users
 // delete documents created older than 2 days
 filterDeleteMany := bson.M{"created_at": bson.M{
 "$lt": time.Now().Add(-2 * 24 * time.Hour),
 }}
 if res, err := DeleteManyUsers(filterDeleteMany); err != nil {
 return
 } else {
 fmt.Printf("deleted count: %d\n", res.DeletedCount)
 }
}
// models
func DeleteManyUsers(filter bson.M) (*mongo.DeleteResult, error) {
 res, err := UserColl.DeleteMany(ctx, filter)
 return res, err
}

查

单个查找

// controllers
func ExampleMongo() {
 // find one user
 id, err = primitive.ObjectIDFromHex("[user id]")
 if err != nil {
 return
 }
 filterFindOne := bson.M{"_id": id}
 if res, err := FindOneUser(filterFindOne); err != nil {
 return
 } else {
 fmt.Printf("post: %+v\n", res)
 }
}
// models
func FindOneUser(filter bson.M) (User, error) {
 Msg := User{}
 result := UserColl.FindOne(ctx, filter)
 err := result.Decode(&Msg)
 return Msg, err
}

多个查找

// controllers
func ExampleMongo() {
 // find many user
 filterFindMany := bson.M{"[key]": "[value]"}
 if res, err := FindManyUsers(filterFindMany); err != nil {
 return
 } else {
 fmt.Printf("post: %+v\n", res)
 }
}
// models
func FindManyUsers(filter bson.M) ([]User, error) {
 cursor, err := UserColl.Find(ctx, filter)
 if err != nil {
 return nil, err
 }
 // iterate through all documents
 var res []User
 for cursor.Next(ctx) {
 var p User
 // decode the document into given type
 if err := cursor.Decode(&p); err != nil {
 return nil, err
 }
 res = append(res, p)
 }
 return res, nil
}

改

单个更改

// controllers
func ExampleMongo() {
 // update one user
 filter := bson.M{"[key]": "[value]"}
 update := bson.M{"[key]": "[value]"}
 if res, err := UpdateOneUser(filter, update); err != nil {
 return
 } else {
 fmt.Printf("modified count: %d\n", res.ModifiedCount)
 }
}
// models
func UpdateOneUser(filter bson.M, update bson.M) (*mongo.UpdateResult, error) {
 res, err := UserColl.UpdateOne(ctx, filter, update)
 return res, err
}

多个更改

// controllers
func ExampleMongo() {
 // update many users
 filter := bson.M{"[key]": "[value]"}
 update := bson.M{"[key]": "[value]"}
 if res, err := UpdateManyUsers(filter, update); err != nil {
 return
 } else {
 fmt.Printf("modified count: %d\n", res.ModifiedCount)
 }
}
// models
func UpdateManyUsers(filter bson.M, update bson.M) (*mongo.UpdateResult, error) {
 res, err := UserColl.UpdateMany(ctx, filter, update)
 return res, err
}

示例源码

Github: MongoDB Go Driver

参考文档

Using the official MongoDB Go driver

有疑问加站长微信联系(非本文作者)

• 请尽量让自己的回复能够对别人有帮助
• 支持 Markdown 格式, **粗体**、~~删除线~~、`单行代码`
• 支持 @ 本站用户;支持表情(输入 : 提示),见 Emoji cheat sheet
• 图片支持拖拽、截图粘贴等方式上传