Basic CRUD Operations Using Golang, Gin Gonic, and GORM

Building web applications in Golang is both fun and efficient. Using powerful frameworks like Gin Gonic for the web layer and GORM for ORM (Object-Relational Mapping) makes it easier to create robust and maintainable applications. In this tutorial, we'll demonstrate how to implement basic CRUD operations in a book management system.

Project Structure

We will organize our project using the following structure to maintain clean and manageable code:

belajar-go/
│
├── cmd/
│     └── main.go
├── configs/
│     └── dbConfig.go
├── internal/
│     ├── delivery/
│     │     ├── handlers/
│     │     │     └── bookHandler/
│     │     │          └── bookHandler.go
│     │     ├── data/
│     │     │     ├── request/
│     │     │     │     └── bookReq/
│     │     │     │          └── bookRequest.go
│     │     │     └── response/
│     │     │          ├── bookRes/
│     │     │          │     └── bookResponse.go
│     │     │          └── response.go
│     │     └── router/
│     │           ├── bookRouter/
│     │           │          └── bookRouter.go
│     │           └── router.go
│     ├── domain/
│     │     ├── models/
│     │     │     └── books.go
│     │     ├── repositories/
│     │     │     ├── bookRepo/
│     │     │     │      └── bookRepo.go
│     │     └── services/
│     │           ├── bookService/
│     │           │      └── bookService.go
│     └── infrastructure/
│           └── database/
│                  ├── database.go
│                  └── migrations.go
├── pkg/
│     ├── utils/
│     │     └── base.go
│     └── helpers/
│           └── errorPanic.go
├── .env.example
├── .gitignore
├── go.mod
└── go.sum

Setting Up the Project

Initialize the project:

   go mod init github.com/your-username/belajar-go
   go get -u github.com/gin-gonic/gin
   go get -u gorm.io/gorm
   go get -u gorm.io/driver/postgres

Database Configuration (configs/dbConfig.go):

   package configs

   import (
       "gorm.io/driver/postgres"
       "gorm.io/gorm"
   )

   func ConnectDB() (*gorm.DB, error) {
       dsn := "host=localhost user=gorm password=gorm dbname=gorm port=9920 sslmode=disable TimeZone=Asia/Shanghai"
       db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
       if err != nil {
           return nil, err
       }
       return db, nil
   }

Models (internal/domain/models/books.go):

   package models

   import (
       "time"
   )

   type Book struct {
       ID        uint      `gorm:"primaryKey"`
       UUID      string    `gorm:"type:uuid;default:uuid_generate_v4()"`
       Title     string    `gorm:"size:255"`
       Author    string    `gorm:"size:255"`
       Year      int
       CreatedAt time.Time
       UpdatedAt time.Time
   }

Repositories (internal/domain/repositories/bookRepo.go):

   package repositories

   import (
       "github.com/your-username/belajar-go/internal/domain/models"
       "gorm.io/gorm"
   )

   type BookRepository struct {
       Db *gorm.DB
   }

   func NewBookRepository(Db *gorm.DB) *BookRepository {
       return &BookRepository{Db: Db}
   }

   // Implement CRUD operations

Services (internal/domain/services/bookService.go):

   package services

   import (
       "github.com/your-username/belajar-go/internal/domain/models"
       "github.com/your-username/belajar-go/internal/domain/repositories"
   )

   type BookService struct {
       repo *repositories.BookRepository
   }

   func NewBookService(repo *repositories.BookRepository) *BookService {
       return &BookService{repo: repo}
   }

   // Implement service methods

Handlers (internal/delivery/handlers/bookHandler.go):

   package handlers

   import (
       "net/http"

       "github.com/gin-gonic/gin"
       "github.com/your-username/belajar-go/internal/domain/models"
       "github.com/your-username/belajar-go/internal/domain/services"
   )

   type BookHandler struct {
       bookService *services.BookService
   }

   func NewBookHandler(bookService *services.BookService) *BookHandler {
       return &BookHandler{bookService: bookService}
   }

   // Implement handler methods

Router (internal/delivery/router/bookRouter.go):

   package router

   import (
       "github.com/gin-gonic/gin"
       "github.com/your-username/belajar-go/internal/delivery/handlers"
       "github.com/your-username/belajar-go/internal/domain/repositories"
       "github.com/your-username/belajar-go/internal/domain/services"
       "gorm.io/gorm"
   )

   func BookRouter(group *gin.RouterGroup, db *gorm.DB) {
       // Setup routing
   }

Main (cmd/main.go):

   package main

   import (
       "github.com/gin-gonic/gin"
       "github.com/your-username/belajar-go/configs"
       "github.com/your-username/belajar-go/internal/delivery/router"
   )

   func main() {
       // Setup server
   }

Conclusion

By following this guide, you've learned how to create a basic CRUD application using Golang, Gin Gonic, and GORM. This structure helps in maintaining and scaling your application effectively. Happy coding!

For full code klick here

wahid @awahids