How to execute FindOne() with logical query selector($or) in Official Go MongoDB driver?

Question

I am a beginner in mongo with go. I am trying to find one document where "username" or email will be matched. But can't figure out the way to implement this condition to filter.

Here is my document model:

type User struct {
    Username  string    `json:"username" bson:"username"`
    Email     string    `json:"email" bson:"email"`
    Password  string    `json:"password" bson:"password"`
    CreatedAt time.Time `json:"created_at" bson:"created_at"`
    UpdatedAt time.Time `json:"updated_at" bson:"updated_at"`
}

And the query:

filter := bson.D{
   {"username", user.Username},
   {"$or": {"email", user.Email}},
}

err = userCollection.FindOne(context.TODO(), filter).Decode(&user)

Maryam · Answer 1 · 2020-07-20T10:01:58.807

2

you should use $or$ as below:

filter := bson.D{
   {"$or":[{"username": user.Username},{"email": user.Email}]},}

edited Jul 20 '20 at 10:01

answered Jul 20 '20 at 08:08

Maryam

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19

It throws an error with `syntax error: unexpected {, expecting expression`. – Abid Jul 20 '20 at 09:12
add semicolon at the end – Maryam Jul 20 '20 at 10:02

score 0 · Answer 2 · answered Jul 20 '20 at 10:26

Finally this method worked for me.

filter := bson.D{{
        "$or",
        bson.A{
            bson.D{
                {"username", user.Username},
            },
            bson.D{
                {"email", user.Email},
            },
        },
    }}

Some info for constructing commands:

D: A BSON document. This type should be used in situations where order matters, such as MongoDB commands.
M: An unordered map. It is the same as D, except it does not preserve order.
A: A BSON array.
E: A single element inside a D.

How to execute FindOne() with logical query selector($or) in Official Go MongoDB driver?

2 Answers2