golang框架中如何优化数据库查询

type User struct {
  ID uint
  Name string
  Email string
}

// 查询所有用户
users := []User{}
db.Find(&users)

stmt, err := db.Prepare("SELECT * FROM users WHERE id = ?")
if err != nil {
  // Handle error
}

id := 1
rows, err := stmt.Query(id)
if err != nil {
  // Handle error
}

// 添加对 users 表的 id 列的索引
db.Exec("CREATE INDEX idx_users_id ON users(id)")

cache := cache.New(5*time.Minute, 10*time.Minute)
cacheKey := "all-users"

users := []User{}
if err := cache.Get(cacheKey, &users); err != nil {
  // Query the database
  db.Find(&users)

  // Add the results to the cache
  cache.Set(cacheKey, users, cache.DefaultExpiration)
}

// 优化后的查询，避免嵌套查询
users := []User{}
db.Table("users").
  Select("users.id", "users.name", "posts.title").
  Joins("JOIN posts ON users.id = posts.user_id").
  Where("posts.title LIKE '%golang%'").
  Find(&users)

// 优化前的查询
users := []User{}
db.Find(&users)

// 优化后的查询，使用 GORM ORM
users := []User{}
GormDB.Find(&users)