写一段代码：使用golang对mysql进行增删改查

package mainimport ( "database/sql" "fmt" _ "github.com/go-sql-driver/mysql" )func main() { db, err := sql.Open("mysql", "user:password@tcp(127.0.0.1:3306)/dbname") if err != nil { panic(err.Error()) } defer db.Close() // 增 stmt, err := db.Prepare("INSERT INTO users(name, age) VALUES(?, ?