golang 接 mongodb 簡單學習

內容說明

記錄用 golang 串接 mongodb，也會提供必要的註解

資料夾、文件結構圖

.
├── CRUD
│   └── crud.go
├── go.mod
├── go.sum
└── main.go

1 directory, 4 files

main.go 程式碼

package main

import (
	crud "binarytree/CRUD"
	"context"
	"fmt"

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

func main() {
	// credential := options.Credential{
	// 	Username: "xxxx",
	// 	Password: "bbbb",
	// }

	//clientOpts := options.Client().ApplyURI("mongodb://localhost:27017").SetAuth(credential) //有帳號的情況
	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017") //沒有帳號密碼下直接連
	ctx := context.Background()
	client, err := mongo.Connect(ctx, clientOpts)
	err = client.Ping(ctx, nil) //若沒有成功連線，則會返回error
	if err != nil {
		fmt.Println(err) //Connect似乎不吐error
		return
	}

	//create schema
	_, collection := crud.CreateDatabase(client, "test", "member")

	//create data
	person := crud.Person{Name: "david", Age: 23, Email: "gmail.com"}
	person.ID = crud.InsertDocument(collection, person)
	fmt.Println(person.ID)

	//find data
	otherOne := crud.FindDocumentByID(collection, person.ID)
	fmt.Println(otherOne.Name, otherOne.Email)

	//update data
	crud.UpdateDocument(collection, person.ID, 50)

}

// golang 連 mongodb
//https://datapool.tw/2023/08/22/golang-mongodb-connection-%E5%8A%A0-ping-%E7%A2%BA%E8%AA%8D%E9%80%A3%E7%B7%9A/
//

crud.go 程式碼

package crud

import (
	"context"
	"fmt"
	"log"

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

func CreateDatabase(client *mongo.Client, dbName string, collectionName string) (*mongo.Database, *mongo.Collection) {
	database := client.Database(dbName)
    //collection = sql 的 schema
	collection := database.Collection(collectionName)
	return database, collection
}

type Person struct {
	ID    primitive.ObjectID `bson:"_id,omitempty"` //mongodb 的 unique id 格式
	Name  string             `bson:"name"`
	Age   int                `bson:"age"`
	Email string             `bson:"email"`
}

func InsertDocument(collection *mongo.Collection, person Person) primitive.ObjectID {
	insertResult, err := collection.InsertOne(context.Background(), person)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("Inserted document with ID:", insertResult.InsertedID)
	return insertResult.InsertedID.(primitive.ObjectID)
	//return fmt.Sprintf("%s", insertResult.InsertedID)
}

func FindDocumentByID(collection *mongo.Collection, id primitive.ObjectID) Person {
	var result Person

	filter := bson.D{{"_id", id}}
	err := collection.FindOne(context.Background(), filter).Decode(&result)
	if err != nil {
		log.Fatal(err)
	}

	return result
}

func UpdateDocument(collection *mongo.Collection, id primitive.ObjectID, newAge int) {
	filter := bson.D{{"_id", id}}
	update := bson.D{
		{"$set", bson.D{ // $set 只修改資料內的特定部分
			{"age", newAge},
		}},
	}

	updateResult, err := collection.UpdateOne(context.Background(), filter, update)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("Matched %v document(s) and modified %v document(s)\n", updateResult.MatchedCount, updateResult.ModifiedCount)
}

func DeleteDocument(collection *mongo.Collection, id primitive.ObjectID) {
	filter := bson.D{{"_id", id}}
	deleteResult, err := collection.DeleteOne(context.Background(), filter)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("Deleted %v document(s)\n", deleteResult.DeletedCount)
}

參考連結

Golang MongoDB connection 加 Ping 確認連線 by DataPool inc.