Go 언어는 데이터베이스의 추가, 삭제, 수정 및 쿼리 작업을 어떻게 구현합니까?

import (
    "database/sql"
    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "username:password@tcp(127.0.0.1:3306)/dbname")
    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()
}

func insertData(db *sql.DB, name string, age int) error {
    _, err := db.Exec("INSERT INTO users (name, age) VALUES (?, ?)", name, age)
    return err
}

func deleteData(db *sql.DB, id int) error {
    _, err := db.Exec("DELETE FROM users WHERE id = ?", id)
    return err
}

func updateData(db *sql.DB, id int, name string, age int) error {
    _, err := db.Exec("UPDATE users SET name = ?, age = ? WHERE id = ?", name, age, id)
    return err
}

func queryData(db *sql.DB, id int) (string, int, error) {
    var name string
    var age int
    err := db.QueryRow("SELECT name, age FROM users WHERE id = ?", id).Scan(&name, &age)
    return name, age, err
}