go語言操作mongodb

程式碼

// mongodb CRUD

// ctx bson.D ?

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type Student struct {
	Name string
	City string
	Score float32	
}

func CheckError(err error, line int){
	if err != nil {
		fmt.Println("error line:", line)
		log.Fatal(err)
	}
}

func query(ctx context.Context, collection *mongo.Collection) {
	// https://blog.csdn.net/ootw/article/details/115902576, 需要規範化的編寫才不會飄黃
	sort := bson.D{{Key:"score", Value:1}}	// 排序， 1升序， -1降序
	filter := bson.D{{Key:"score", Value:bson.D{{Key:"$gt", Value:3}}}}  // 過濾條件 score > 3

	findOption := options.Find()
	findOption.SetSort(sort)
	findOption.SetLimit(10) // 最多返回10個
	findOption.SetSkip(0)	// 跳過前三個

	cursor, err := collection.Find(ctx, filter, findOption)
	if err != nil {
		log.Fatal(err)
	}

	// 關閉迭代器
	defer cursor.Close(ctx)

	for cursor.Next(ctx) {
		var doc Student
		err := cursor.Decode(&doc)
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("%s %s %.2f\n", doc.Name, doc.City, doc.Score)
	}
}


func create(ctx context.Context, collection *mongo.Collection) {
	// 插入一個文件
	doc := Student{
		Name: "啊哈",
		City: "香港",
		Score: 86,
	}

	ret, _ := collection.InsertOne(ctx, doc)
	// CheckError(err, 64)

	// 每個doc都會有一個全世界唯一的ID（時間+空間唯一）
	fmt.Printf("insert id %v\n", ret.InsertedID)

	// 插入多個doc
	docs := []interface{}{
		Student{
			Name: "小C",
			City: "上海",
			Score: 90,
		},
		Student{
			Name: "小D",
			City: "杭州",
			Score: 89,
		},
	}

	manyRes, err := collection.InsertMany(ctx, docs)
	fmt.Printf("insert many ids %v\n", manyRes.InsertedIDs)
	CheckError(err, 85)
}

func update(ctx context.Context, collection *mongo.Collection) {
	fileter := bson.D{{Key:"city", Value:"杭州"}}
	update := bson.D{{Key:"$inc", Value: bson.D{{Key: "score", Value: 89}}}}

	res, err := collection.UpdateMany(ctx, fileter, update)
	CheckError(err, 96)
	fmt.Printf("update %d doc \n", res.ModifiedCount)	
}

func delete(ctx context.Context, collection *mongo.Collection) {
	filter := bson.D{{Key:"name", Value: "小D"}}
	res, err := collection.DeleteMany(ctx, filter)
	CheckError(err, 105)
	fmt.Printf("delete %d doc \n", res.DeletedCount)
}

func main() {
	// 不懂
	ctx := context.Background()

	// 設定客戶端連線配置
	clientOptions := options.Client().ApplyURI("mongodb://172.30.1.128:27017")
	clientOptions.SetConnectTimeout(time.Second)
	clientOptions.SetAuth(options.Credential{Username: "admin", Password: "Tck151##a", AuthSource: "admin"})

	// 連線到mongodb
	client, err := mongo.Connect(ctx, clientOptions)
	if err != nil {
		log.Fatal(err)
	}

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

	// 釋放連線
	defer client.Disconnect(ctx)

	collection := client.Database("test").Collection("student")
	
	query(ctx, collection)
	// create(ctx, collection)
	// update(ctx, collection)
	// delete(ctx, collection)
}
``
 

本文來自部落格園，作者：zhanghuiyan，轉載請註明原文連結：https://www.cnblogs.com/zhanghuiyan/p/15179684.html