Updates to LogRocket's Gin Gonic tutorial article

controller.go

package controllers

import (
	"Go-Tutorials/models"
	"github.com/gin-gonic/gin"
	"net/http"
)

type CreateBookInput struct {
	Title  string `json:"title" binding:"required"`
	Author string `json:"author" binding:"required"`
}

type UpdateBookInput struct {
	Title  string `json:"title"`
	Author string `json:"author"`
}

func FindBooks(c *gin.Context) {
	var books []models.Book
	models.DB.Find(&books)

	c.JSON(http.StatusOK, gin.H{"data": books})
}

func CreateBook(c *gin.Context) {
	// Validate input
	var input CreateBookInput
	if err := c.ShouldBindJSON(&input); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Create book
	book := models.Book{Title: input.Title, Author: input.Author}
	models.DB.Create(&book)

	c.JSON(http.StatusOK, gin.H{"data": book})
}

func FindBook(c *gin.Context) { // Get model if exist
	var book models.Book

	if err := models.DB.Where("id = ?", c.Param("id")).First(&book).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Record not found!"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"data": book})
}

func UpdateBook(c *gin.Context) {
	// Get model if exist
	var book models.Book
	if err := models.DB.Where("id = ?", c.Param("id")).First(&book).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Record not found!"})
		return
	}

	// Validate input
	var input UpdateBookInput
	if err := c.ShouldBindJSON(&input); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	models.DB.Model(&book).Updates(input)

	c.JSON(http.StatusOK, gin.H{"data": book})
}

func DeleteBook(c *gin.Context) {
	// Get model if exist
	var book models.Book
	if err := models.DB.Where("id = ?", c.Param("id")).First(&book).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Record not found!"})
		return
	}

	models.DB.Delete(&book)

	c.JSON(http.StatusOK, gin.H{"data": true})
}

main.go

package main

import (
	"Go-Tutorials/controllers"
	"Go-Tutorials/models"
	"github.com/gin-gonic/gin"
)

func main() {
	// ...
	r := gin.Default()
	models.ConnectDatabase()

	r.GET("/books", controllers.FindBooks)
	r.POST("/books", controllers.CreateBook)
	r.GET("/books/:id", controllers.FindBook)
	r.PATCH("/books/:id", controllers.UpdateBook)
	r.DELETE("/books/:id", controllers.DeleteBook) // new

	err := r.Run()
	if err != nil {
		return
	}
}

model.go

package models

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

type Book struct {
	ID     uint   `json:"id" gorm:"primary_key"`
	Title  string `json:"title"`
	Author string `json:"author"`
}

var DB *gorm.DB

func ConnectDatabase() {

	database, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})

	if err != nil {
		panic("Failed to connect to database!")
	}

	err = database.AutoMigrate(&Book{})
	if err != nil {
		return
	}

	DB = database
}