[FIXED] How to run Find.().One() in the new go-mongo-driver

Issue

Currently we are in the process of migrating the mgo(globalsign) driver to go mongo-driver

And I want some alternative way to do Find.().One()

I tried something like below but it did not help

    login = model.LoginModel{}
    err = mongo.Collection.Find(bson.M{"name": MAXCOUNT}).Decode(&loginCount) 

Returned me back with the below error ,

 error was: cannot transform type []interface {} to a BSON Document: WriteArray can only write a Array while positioned on a Element or Value but is positioned on a TopLevel

not sure whether the new Decode method allows a struct value ?

my struct looks something like below

type LoginModel struct {
Username    string  `json:"username"`
Password    string  `json:"password"`

}

Do i need to have corresponding bson values too ?

Trying to run Find.().One() in go-mongo-driver

Solution

Collection.Find() is designed to query multiple elements. It returns a mongo.Cursor which you can use to iterate over the results or get all using Cursor.All().

If you need a single result, use Collection.FindOne() instead.

For example:

ctx := context.Background() // Use / setup your context
c := ... // acquire mongo.Collection

var login model.LoginModel
err = c.FindOne(ctx, bson.M{"name": MAXCOUNT}).Decode(&login)
// check error

Answered By - icza

Answer Checked By - David Goodson (PHPFixing Volunteer)