Go Gin + SQL 全栈：CRUD、事务、迁移、监控全攻略

Go Gin SQL 全栈CRUD、事务、迁移、监控全攻略Gin SQL 是后端项目最常见的搭配。本文带你看一眼真实项目的完整闭环。一、项目布局cmd/server internal/{handler, service, repo} internal/config pkg/types configs/config.yaml二、main.gofuncmain(){cfg,_:config.Load()db,_:sql.Open(mysql,cfg.DB.DSN)db.SetMaxOpenConns(50)db.SetMaxIdleConns(10)deferdb.Close()userRepo:repo.NewUserRepo(db)userSvc:service.NewUserService(userRepo)handler:handler.NewUserHandler(userSvc)r:gin.Default()handler.Register(r)log.Println(server listens on :8080)http.ListenAndServe(:8080,r)}三、配置加载typeConfigstruct{DBstruct{DSNstringMaxint}PortstringAppEnvstring}funcLoad()(*Config,error){viper.SetConfigName(config)viper.AddConfigPath(./configs)err:viper.ReadInConfig()varc Configreturnc,err}四、Repo 层typeUserRepointerface{Find(idint)(User,error);Create(u User)(int64,error)}typeuserRepostruct{db*sql.DB}funcNewUserRepo(db*sql.DB)UserRepo{returnuserRepo{db:db}}func(r*userRepo)Find(idint)(User,error){varu User err:r.db.QueryRow(SELECT id, name FROM users WHERE id?,id).Scan(u.ID,u.Name)returnu,err}func(r*userRepo)Create(u User)(int64,error){res,err:r.db.Exec(INSERT INTO users(name) VALUES(?),u.Name)iferr!nil{return0,err}returnres.LastInsertId()}五、Service 层typeuserServicestruct{repo UserRepo}func(s*userService)CreateUser(ctx context.Context,namestring)(int64,error){ifname{return0,ErrEmptyName}returns.repo.Create(User{Name:name})}六、Handler 层func(h*UserHandler)Register(r*gin.Engine){r.GET(/users/:id,h.Get)r.POST(/users,h.Post)}func(h*UserHandler)Get(c*gin.Context){id,_:strconv.Atoi(c.Param(id))u,err:h.svc.Find(c.Request.Context(),id)iferr!nil{c.JSON(http.StatusNotFound,gin.H{err:not found});return}c.JSON(http.StatusOK,u)}func(h*UserHandler)Post(c*gin.Context){varreqstruct{Namestringjson:name}iferr:c.ShouldBindJSON(req);err!nil{c.JSON(400,gin.H{err:err.Error()});return}id,err:h.svc.CreateUser(c.Request.Context(),req.Name)iferr!nil{c.JSON(500,gin.H{err:err.Error()});return}c.JSON(200,gin.H{id:id})}七、事务与一致性func(s*userService)TransferMoney(ctx context.Context,from,toint,amountint64)error{tx,err:s.db.BeginTx(ctx,nil)iferr!nil{returnerr}defertx.Rollback()if_,err:tx.Exec(UPDATE balances SET amountamount-? WHERE user?,amount,from);err!nil{returnerr}if_,err:tx.Exec(UPDATE balances SET amountamount? WHERE user?,amount,to);err!nil{returnerr}returntx.Commit()}八、迁移 版本管理migrate create-extsql-dirmigrations-seqadd_users migrate-pathmigrations-databasemysql://user:pwdhost:3306/appup九、监控importgithub.com/prometheus/client_golang/prometheus/promhttphttp.Handle(/metrics,promhttp.Handler())业务层用中间件记录 QPS、error_rater.Use(func(c*gin.Context){deferfunc(){requestCount.WithLabelValues(c.Request.Method,c.FullPath(),strconv.Itoa(c.Writer.Status())).Inc()}()c.Next()})十、链路追踪importgo.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelginr.Use(otelgin.Middleware(user-svc))业务也加上ctx,span:tracer.Start(ctx,service.CreateUser)deferspan.End()十一、中间件限流importgolang.org/x/time/ratelimiter:rate.NewLimiter(10,20)r.Use(func(c*gin.Context){if!limiter.Allow(){c.AbortWithStatusJSON(429,gin.H{err:rate limited})return}c.Next()})十二、CI/CDtest:script:-go test ./...-racebuild:script:-go build-o app .deploy:script:-kubectl apply-f deployment.yaml十三、踩坑清单忘记读取 ctx所有 repo / service 方法必带 ctx业务事务跨多个流程 → 改 sagajson.bigint 精度丢失十四、未来Serverless 部署一体化可观测平台十五、总结与展望三层架构 Gin SQL 是 Go 后端的金标准。掌握它能为以后快速搭建业务铺路。十六、参考文献Gin 文档Go database/sql 标准库sqlmigrate