Go言語を使用してオブジェクト指向データベースアクセスを実装する方法

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

func main() {
    db, err := sql.Open("mysql", "root:password@tcp(localhost:3306)/test")
    if err != nil {
        panic(err)
    }
    defer db.Close()
    
    // 继续其他数据库操作
}

// 执行无返回结果的SQL语句
res, err := db.Exec("INSERT INTO users (name, age) VALUES (?, ?)", "Tom", 20)
if err != nil {
    panic(err)
}
lastInsertID, _ := res.LastInsertId()
affectedRows, _ := res.RowsAffected()
fmt.Printf("Last Insert ID: %d
", lastInsertID)
fmt.Printf("Affected Rows: %d
", affectedRows)

// 执行有返回结果的SQL语句
rows, err := db.Query("SELECT * FROM users")
if err != nil {
    panic(err)
}
defer rows.Close()
for rows.Next() {
    var name string
    var age int
    err := rows.Scan(&name, &age)
    if err != nil {
        panic(err)
    }
    fmt.Printf("User: %s, Age: %d
", name, age)
}

type User struct {
    Name string
    Age  int
}

// 执行有返回结果的SQL语句
rows, err := db.Query("SELECT * FROM users")
if err != nil {
    panic(err)
}
defer rows.Close()
for rows.Next() {
    var user User
    err := rows.Scan(&user.Name, &user.Age)
    if err != nil {
        panic(err)
    }
    fmt.Printf("User: %+v
", user)
}

type User struct {
    Name string
    Age  int
}

func (u *User) Insert(db *sql.DB) (int64, error) {
    res, err := db.Exec("INSERT INTO users (name, age) VALUES (?, ?)", u.Name, u.Age)
    if err != nil {
        return 0, err
    }
    return res.LastInsertId()
}

func (u *User) FindAll(db *sql.DB) ([]User, error) {
    rows, err := db.Query("SELECT * FROM users")
    if err != nil {
        return nil, err
    }
    defer rows.Close()
    
    var users []User
    for rows.Next() {
        var user User
        err := rows.Scan(&user.Name, &user.Age)
        if err != nil {
            return nil, err
        }
        users = append(users, user)
    }
    return users, nil
}

func main() {
    db, err := sql.Open("mysql", "root:password@tcp(localhost:3306)/test")
    if err != nil {
        panic(err)
    }
    defer db.Close()
    
    user := User{Name: "Tom", Age: 20}
    lastInsertID, err := user.Insert(db)
    if err != nil {
        panic(err)
    }
    fmt.Printf("Last Insert ID: %d
", lastInsertID)
    
    users, err := user.FindAll(db)
    if err != nil {
        panic(err)
    }
    for _, u := range users {
        fmt.Printf("User: %+v
", u)
    }
}