How to page a cursor in official mongo-go-driver

问题

Inspecting the interface Cursor in mongo-go-driver:

https://github.com/mongodb/mongo-go-driver/blob/master/mongo/cursor.go#L37

There's no Limit or Skip functions.

How can I page the results?

I think I will face the same problem when trying to Sort or Count.

Is there a way? or, is this simply not yet implemented in the official driver?

回答1:

Most of the find options you can check in package options https://github.com/mongodb/mongo-go-driver/tree/master/mongo/options

client, err := mongo.Connect(context.Background(), "mongodb://localhost:27017", nil)
// check err
db := client.Database("examples")

coll := db.Collection("inventory")
{
    cursor, err := coll.Find(
        context.Background(),
        options.SetSort(bson.NewDocument(bson.EC.Int64("x", 1))),
        options.SetLimit(30),
        options.SetSkip(5),
    )

    // cursor decode...

}

Count with filter

count, err :=coll.Count(context.Background(),bson.NewDocument(bson.EC.String("foo", "bar")))

Count from document metadata

count, err := coll.EstimatedDocumentCount(context.Background(),countopt.MaxTimeMs(100))

Edit:

Mongo-go-driver stable v1.0.0 released where they separated the BSON library, Please refar to official documentation

来源：https://stackoverflow.com/questions/51956805/how-to-page-a-cursor-in-official-mongo-go-driver