A wrapper to make it easier to use go.mongodb.org/mongo-driver/v2
You can use the FindMany Decode chain to decode an array of documents from mongodb collection.
collection := client.Database("test").Collection("test") var data []Elem if err := nosql.FindMany(ctx, collection, bson.D{}).Decode(&data); err != nil { return err } // Some using of documents slice for _, e := range data { fmt.Println(e.ID) } It is like calling FindOne Decode chain to decode a single document in a standard mongodb driver.
FindMany wraps the func (*Collection) Find results, so the parameters are the same.
Data parameter of func Decode may be a pointer to an slice of struct. Also data parameter may be a pointer to an slice of pointers to a struct, see below.
If no documents are found, an empty slice is returned.
package main import ( "context" "fmt" "github.com/codeation/nosql/v2" "go.mongodb.org/mongo-driver/v2/bson" "go.mongodb.org/mongo-driver/v2/mongo" "go.mongodb.org/mongo-driver/v2/mongo/options" ) type Elem struct { Num int `bson:"num"` Str string `bson:"str"` } func main() { client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://localhost:27017/")) if err != nil { return } ctx := context.Background() if err = client.Connect(ctx); err != nil { return } defer client.Disconnect(ctx) collection := client.Database("test").Collection("test") var data []*Elem if err := nosql.FindMany(ctx, collection, bson.D{}).Decode(&data); err != nil { return } for _, e := range data { fmt.Println(e.Num, e.Str) } } package main import ( "context" "fmt" "github.com/codeation/nosql/v2" "go.mongodb.org/mongo-driver/v2/bson" "go.mongodb.org/mongo-driver/v2/mongo" "go.mongodb.org/mongo-driver/v2/mongo/options" ) type Elem struct { Num int `bson:"num"` Str string `bson:"str"` } func main() { client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://localhost:27017/")) if err != nil { return } ctx := context.Background() if err = client.Connect(ctx); err != nil { return } defer client.Disconnect(ctx) db := nosql.NewDatabase(client.Database("test")) // wrap mongo.Database reference collection := db.Collection("test") var data []*Elem if err := collection.FindMany(ctx, bson.D{}).Decode(&data); err != nil { return } for _, e := range data { fmt.Println(e.Num, e.Str) } } You can use the AggregateMany Decode chain to decode an array of documents from aggregate command results.
collection := client.Database("test").Collection("test") var data []Elem if err := nosql.AggregateMany(ctx, collection, bson.D{}).Decode(&data); err != nil { return err } NextSequence returns next ID value.
id, err := db.NextSequence(ctx, "elemid") if err != nil { return err } e := &Element { ID: id, ... // Other fields } This can be useful when you plan to use int64 values as IDs, or you need to know the new ID before inserting the document.
NextSequence uses the atomic operation $inc.
Make sure that the "counters" collection has an index by "id" field:
db.counters.createIndex( { id: 1 } )