如何使用mongo-driver连接到其他软件包

Question

I am using Mongo-driver with gin framework. I have written code to connect mongodb in DB package and if I write query inside db/connect.go, it works but when I use same dbcon in other package it doesn't.

db/connect.go:

var dbcon *mongo.Database
func ConfigDB() (*mongo.Database) {
    ctx := context.Background()
    client, err := mongo.Connect(
            ctx,
        options.Client().ApplyURI("mongodb://localhost:27017/todo"),
    )
    if err != nil {
        log.Fatal(err)
    }
    dbcon = client.Database("todo")

}

if I use the code below in same db/connect.go, then it works but when I use the same code in handler/task.go, then it won't.

func CreateTask() () {
    ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    defer cancel()
    res, err := dbcon.Collection("ttest").InsertOne(ctx, bson.D{
        {"task", "test4"},
        {"createdAt", "test"},
        {"modifiedAt","test3"},
    })
    if err != nil {
        fmt.Println( err))
    }
}

I have to implement a mongo-driver in my project, but due to above issue I am facing problem to implement.

Answer 1

You'll have to import to import the db/connect.go file into the handler/task.go. This is not working because they are in different packages. In my opinion you could refactor your code like this

func ConfigDB() (*mongo.Database) {
    ctx := context.Background()
    client, err := mongo.Connect(
            ctx,
        options.Client().ApplyURI("mongodb://localhost:27017/todo"),
    )
    if err != nil {
        log.Fatal(err)
    }
    return client.Database("todo")

}

import (
"db/connect"
)

func CreateTask() () {
    ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    defer cancel()
    res, err := ConfigDB().Collection("test").InsertOne(ctx, bson.D{
        {"task", "test4"},
        {"createdAt", "test"},
        {"modifiedAt","test3"},
    })
    if err != nil {
        fmt.Println( err))
    }
}