GO操作mongoDB

GO操作mongo数据库实战

主要是mongo官方文档抄过来的，加上一些自己简单的话术

先决条件

有go环境和mongo环境

创建好go mod文档，导入驱动

 require go.mongodb.org/mongo-driver

写个demo

创建一个main.go

导入本次需要的包，和写上一个结构体做案例

import (
    "context"
    "fmt"
    "log"

    "go.mongodb.org/mongo-driver/bson"
    "go.mongodb.org/mongo-driver/mongo"
    "go.mongodb.org/mongo-driver/mongo/options"
)
// You will be using this Trainer type later in the program
type Trainer struct {
    Name string
    Age  int
    City string
}

连接测试

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

// Connect to MongoDB
client, err := mongo.Connect(context.TODO(), clientOptions)

if err != nil {
    log.Fatal(err)
}

// Check the connection
err = client.Ping(context.TODO(), nil)

if err != nil {
    log.Fatal(err)
}

fmt.Println("Connected to MongoDB!")



//最后可能也需要关闭连接
err = client.Disconnect(context.TODO())

if err != nil {
    log.Fatal(err)
}
fmt.Println("Connection to MongoDB closed.")

指定操作集合以及数据库

//test数据库下的trainers集合
collection := client.Database("test").Collection("trainers")

插入

ash := Trainer{"Ash", 10, "Pallet Town"}
//这里可以使用InsertMany来插入多条
insertResult, err := collection.InsertOne(context.TODO(), ash)
if err != nil {
    log.Fatal(err)
}
fmt.Println("Inserted a single document: ", insertResult.InsertedID)

更新

//更新查询删除的时候会用到filter
filter := bson.D{{"name", "Ash"}}
//更新规则
update := bson.D{
    {"$inc", bson.D{
        {"age", 1},
    }},
}
//这儿只更新一条
updateResult, err := collection.UpdateOne(context.TODO(), filter, update)
if err != nil {
    log.Fatal(err)
}

查找

var result Trainer
//这儿只查找一条
err = collection.FindOne(context.TODO(), filter).Decode(&result)
if err != nil {
    log.Fatal(err)
}

fmt.Printf("Found a single document: %+v\n", result)


//查找多条
findOptions := options.Find()
findOptions.SetLimit(3)
// Here's an array in which you can store the decoded documents
var results []*Trainer
// Passing bson.D{{}} as the filter matches all documents in the collection
cur, err := collection.Find(context.TODO(), bson.D{{}}, findOptions)
if err != nil {
  log.Fatal(err)
}

// Finding multiple documents returns a cursor
// Iterating through the cursor allows us to decode documents one at a time
for cur.Next(context.TODO()) {
  // create a value into which the single document can be decoded
  var elem Trainer
  err := cur.Decode(&elem)
  if err != nil {
    log.Fatal(err)
  }

  results = append(results, &elem)
}

if err := cur.Err(); err != nil {
  log.Fatal(err)
}

// Close the cursor once finished
cur.Close(context.TODO())

fmt.Printf("Found multiple documents (array of pointers): %+v\n", results)
for i := 0; i < len(results); i++ {
  fmt.Println(results[i])
}

删除

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