依赖

• Gin框架: github.com/gin-gonic/gin
• Viper读配置文用的: github.com/spf13/viper
• gorm ORM库: github.com/go-gorm/gorm
• gorm mysql驱动: gorm.io/driver/mysql

码

config/application.yaml

server:
  port: 8081
datasource:
  driverName: mysql
  host: 127.0.0.1
  port: 3306
  database: go_api
  username: root
  password: root
  charset: utf8
  loc: Asia/Shanghai

main.go

func main() {
        // 初始化配置文件
	initConfig()
        // 初始化数据库, 方法在common包下的database.go里
	db := common.InitDB()
	defer db.Close()

        // 初始化默认Gin Engine
	r := gin.Default()
        // 配置中间件, Routes等
	r = CollectRoute(r)
	port := viper.GetString("server.port")
	if port != "" {
		panic(r.Run(":" + port))
	}
	panic(r.Run()) // listen and serve on 0.0.0.0:8080
}

// 设置配置文件的方法
func initConfig() {
	workDir, _ := os.Getwd()
	viper.SetConfigName("application")
	viper.SetConfigType("yml")
	viper.AddConfigPath(workDir + "/config")
	err := viper.ReadInConfig()
	if err != nil {
		panic("")
	}
}

common/database.go

var DB *gorm.DB

func InitDB() *gorm.DB {
        // 各种读配置文件
	driverName := viper.GetString("datasource.driverName")
	host := viper.GetString("datasource.host")
	port := viper.GetString("datasource.port")
	database := viper.GetString("datasource.database")
	username := viper.GetString("datasource.username")
	password := viper.GetString("datasource.password")
	charset := viper.GetString("datasource.charset")
	loc := viper.GetString("datasource.loc")

        // 拼凑字符串
	args := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=%s&parseTime=true&loc=%s",
		username,
		password,
		host,
		port,
		database,
		charset,
		url.QueryEscape(loc))
	fmt.Printf(args)
	db, err := gorm.Open(driverName, args)
	if err != nil {
		panic("fail to connect database, err: " + err.Error())
	}
	db.AutoMigrate(&model.User{})

	DB = db
	return db
}

// db实例的getter
func GetDB() *gorm.DB {
	return DB
}

model/user.go

type User struct {
	gorm.Model
	Name      string `gorm:"type:varchar(20);not null"`
	Telephone string `gorm:"varchar(11);not null;unique"`
	Password  string `gorm:"size:255;not null"`
}

一个Repository的实例

type CategoryRepository struct {
	DB *gorm.DB
}

func NewCategoryRepository() CategoryRepository {
	return CategoryRepository{DB: common.GetDB()}
}

func (c CategoryRepository) Create(name string) (*model.Category, error) {
	category := model.Category{
		Name: name,
	}

	if err := c.DB.Create(&category).Error; err != nil {
		return nil, err
	}

	return &category, nil
}

func (c CategoryRepository) Update(category model.Category, name string) (*model.Category, error) {
	if err := c.DB.Model(&category).Update("name", name).Error; err != nil {
		return nil, err
	}

	return &category, nil
}

func (c CategoryRepository) SelectById(id int) (*model.Category, error) {
	var category model.Category
	if err := c.DB.First(&category, id).Error; err != nil {
		return nil, err
	}

	return &category, nil
}

func (c CategoryRepository) DeleteById(id int) error {
	if err := c.DB.Delete(model.Category{}, id).Error; err != nil {
		return err
	}

	return nil
}

其中, Category model是

type Category struct {
	ID        uint   `json:"id" gorm:"primary_key"`
	Name      string `json:"name" gorm:"type:varchar(50);not null;unique"`
	CreatedAt Time   `json:"created_at" gorm:"type:timestamp"`
	UpdatedAt Time   `json:"updated_at" gorm:"type:timestamp"`
}

参考

请参考gorm文档.