Update Data Ke Dalam Database Di Restful Api Golang — Part 6

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Tahapan Implementasi & Walkthrough Kode

Berikut adalah langkah demi langkah teknis yang dapat Anda ikuti langsung pada codebase Anda:

Tahap 1: Penulisan Kode & Konfigurasi

package controllers

import (
	"errors"
	"net/http"
	"santrikoding/backend-api/models"

	"github.com/gin-gonic/gin"
	"github.com/go-playground/validator/v10"
)

// type validation post input
type ValidatePostInput struct {
	Title   string `json:"title" binding:"required"`
	Content string `json:"content" binding:"required"`
}

// type error message
type ErrorMsg struct {
	Field   string `json:"field"`
	Message string `json:"message"`
}

// function get error message
func GetErrorMsg(fe validator.FieldError) string {
	switch fe.Tag() {
	case "required":
		return "This field is required"
	}
	return "Unknown error"
}

// get all posts
func FindPosts(c *gin.Context) {

	//get data from database using model
	var posts []models.Post
	models.DB.Find(&posts)

	//return json
	c.JSON(200, gin.H{
		"success": true,
		"message": "Lists Data Posts",
		"data":    posts,
	})
}

// store a post
func StorePost(c *gin.Context) {
	//validate input
	var input ValidatePostInput
	if err := c.ShouldBindJSON(&input); err != nil {
		var ve validator.ValidationErrors
		if errors.As(err, &ve) {
			out := make([]ErrorMsg, len(ve))
			for i, fe := range ve {
				out[i] = ErrorMsg{fe.Field(), GetErrorMsg(fe)}
			}
			c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"errors": out})
		}
		return
	}

	//create post
	post := models.Post{
		Title:   input.Title,
		Content: input.Content,
	}
	models.DB.Create(&post)

	//return response json
	c.JSON(201, gin.H{
		"success": true,
		"message": "Post Created Successfully",
		"data":    post,
	})
}

// get post by id
func FindPostById(c *gin.Context) {
	var post models.Post
	if err := models.DB.Where("id = ?", c.Param("id")).First(&post).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Record not found!"})
		return
	}

	c.JSON(200, gin.H{
		"success": true,
		"message": "Detail Data Post By ID : " + c.Param("id"),
		"data":    post,
	})
}

// update post
func UpdatePost(c *gin.Context) {
	var post models.Post
	if err := models.DB.Where("id = ?", c.Param("id")).First(&post).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Record not found!"})
		return
	}

	//validate input
	var input ValidatePostInput
	if err := c.ShouldBindJSON(&input); err != nil {
		var ve validator.ValidationErrors
		if errors.As(err, &ve) {
			out := make([]ErrorMsg, len(ve))
			for i, fe := range ve {
				out[i] = ErrorMsg{fe.Field(), GetErrorMsg(fe)}
			}
			c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"errors": out})
		}
		return
	}

	//update post
	models.DB.Model(&post).Updates(input)

	c.JSON(200, gin.H{
		"success": true,
		"message": "Post Updated Successfully",
		"data":    post,
	})
}

Tahap 2: Penulisan Kode & Konfigurasi

// update post
func UpdatePost(c *gin.Context) {

	//...
	
}

Tahap 3: Penulisan Kode & Konfigurasi

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

Tahap 4: Penulisan Kode & Konfigurasi

var input ValidatePostInput

Tahap 5: Penulisan Kode & Konfigurasi

if err := c.ShouldBindJSON(&input); err != nil {

	//...

}

Tahap 6: Penulisan Kode & Konfigurasi

var ve validator.ValidationErrors
if errors.As(err, &ve) {
    out := make([]ErrorMsg, len(ve))
    for i, fe := range ve {
        out[i] = ErrorMsg{fe.Field(), getErrorMsg(fe)}
    }
    c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{"errors": out})
}
return

Tahap 7: Penulisan Kode & Konfigurasi

//update post
models.DB.Model(&post).Updates(input)

Tahap 8: Penulisan Kode & Konfigurasi

c.JSON(200, gin.H{
        "success": true,
        "message": "Post Updated Successfully",
        "data":    post,
})

Tahap 9: Penulisan Kode & Konfigurasi

package main

import (
	"santrikoding/backend-api/controllers"
	"santrikoding/backend-api/models"

	"github.com/gin-gonic/gin"
)

func main() {
	//inisialiasai Gin
	router := gin.Default()

	//panggil koneksi database
	models.ConnectDatabase()

	//membuat route dengan method GET
	router.GET("/", func(c *gin.Context) {

		//return response JSON
		c.JSON(200, gin.H{
			"message": "Hello World!",
		})
	})

	//membuat route get all posts
	router.GET("/api/posts", controllers.FindPosts)

	//membuat route store post
	router.POST("/api/posts", controllers.StorePost)

	//membuat route detail post
	router.GET("/api/posts/:id", controllers.FindPostById)

	//membuat route update post
	router.PUT("/api/posts/:id", controllers.UpdatePost)

	//mulai server dengan port 3000
	router.Run(":3000")
}

Tahap 10: Penulisan Kode & Konfigurasi

//membuat route update post
router.PUT("/api/posts/:id", controllers.UpdatePost)

Tahap 11: Penulisan Kode & Konfigurasi

{
    "title": "Belajar Restful API Golang - Edit",
    "content": "Di SantriKoding - Edit"
}

Tahap 12: Penulisan Kode & Konfigurasi

{
    "data": {
        "id": 1,
        "title": "Belajar Restful API Golang - Edit",
        "content": "Di SantriKoding - Edit"
    },
    "message": "Post Updated Successfully",
    "success": true
}

Kesimpulan

Dengan mengikuti langkah-langkah terstruktur di atas, implementasi modul Anda akan jauh lebih rapi, aman dari bug umum, serta siap diskalakan ke lingkungan produksi.

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