db, err := bolt.Open("mydb.db", 0600, nil) if err != nil { log.Fatal(err) } defer db.Close() err = db.Update(func(tx *bolt.Tx) error { b, err := tx.CreateBucket([]byte("mybucket")) if err != nil { return err } err = b.Put([]byte("mykey"), []byte("myvalue")) return err }) if err != nil { log.Fatal(err) }This example creates a new Bolt database or opens an existing one named "mydb.db". It then creates a new bucket named "mybucket" and puts a key/value pair into it. The Update function is used to perform these operations within a transaction. In conclusion, the BoltDB package library provides APIs for creating, updating, and querying Bolt databases. The Update function is one of the APIs that allows you to update the database within a transaction using a callback function. By using BoltDB, you can store and retrieve data in a simple and efficient way within your Go application.