Sample Gin Application

main.go

package main

import (
	"github.com/gin-gonic/gin"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"log"
	"net/http"
)

type Companies struct {
	Name    string `gorm:"primary_key" json:"name"`
	Created string `json:"created"`
	Product string `json:"product"`
}

var DBInstance *gorm.DB

func DBConnection() error {
	DBInstance, err := gorm.Open(sqlite.Open("test.db"), &gorm.Config{})
	if err != nil {
		return err
	}

	err = DBInstance.AutoMigrate(&Companies{})
	if err != nil {
		return err
	}

	return nil
}

func GetCompany(ctx *gin.Context) {
	var company Companies
	name := ctx.Param("company")

	if err := DBInstance.Where("name= ?", name).First(&company).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"Failed": "Company not found"})
		return
	}
	ctx.JSON(http.StatusOK, company)

}

func PostCompany(ctx *gin.Context) {
	var company Companies
	if err := ctx.ShouldBindJSON(&company); err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": "Error Decoding JSON"})
		return
	}
	newCompany := Companies{
		Name:    company.Name,
		Created: company.Created,
		Product: company.Product,
	}

	if err := DBInstance.Create(&newCompany).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "Database Migration Error"})
	}
}

func UpdateCompany(ctx *gin.Context) {

	var company Companies
	name := ctx.Param("company")

	if err := DBInstance.Where("company = ?", name).First(&company).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "Company doesn't exist "})
		return
	}

	if err := ctx.ShouldBindJSON(&company); err != nil {
		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if err := DBInstance.Model(&company).Updates(Companies{
		Name:    company.Name,
		Created: company.Created,
		Product: company.Product,
	}).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	ctx.JSON(http.StatusOK, company)

}

func DeleteCompany(ctx *gin.Context) {

	var company Companies
	name := ctx.Param("company")

	if err := DBInstance.Where("company = ?", name).First(&company).Error; err != nil {
		ctx.JSON(http.StatusNotFound, gin.H{"error": "company not found!"})
		return
	}

	if err := DBInstance.Delete(&company).Error; err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	ctx.JSON(http.StatusOK, gin.H{"message": "Company Deleted"})

}

func main() {
	err := DBConnection()
	if err != nil {
		log.Println("Error creating Database Connection")
		log.Fatalln(err)
	}

	router := gin.Default()
	router.GET("api/v1/:company", GetCompany)
	router.POST("/company", PostCompany)
	router.PUT("api/v1/:company", UpdateCompany)
	router.DELETE("api/v1/:company", DeleteCompany)

	log.Fatal(router.Run(":8080"))
}