CRUD RESTful API in Go with the Gorilla Mux Package - Article for RedGate's Simple Talk Blog

mux.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"

	"github.com/gorilla/mux"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

type Human struct {
	ID   uint   `gorm:"primaryKey"`
	Age  int    `json:"age"`
	Name string `json:"name"`
}

var (
	db  *gorm.DB
	err error
)

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

	err = db.AutoMigrate(&Human{})
	if err != nil {
		return err
	}

	return nil
}

func getHuman(writer http.ResponseWriter, request *http.Request) {
	vars := mux.Vars(request)
	id := vars["id"]
	var human Human
	db.First(&human, id)
	err := json.NewEncoder(writer).Encode(human)
	if err != nil {
		log.Println(err)
	}
}

func createHuman(writer http.ResponseWriter, request *http.Request) {
	var human Human
	err = json.NewDecoder(request.Body).Decode(&human)
	if err != nil {
		log.Println(err)
	}
	db.Create(&human)
	err := json.NewEncoder(writer).Encode(human)
	if err != nil {
		log.Println(err)
	}

}

func updateHuman(writer http.ResponseWriter, request *http.Request) {

	vars := mux.Vars(request)
	id := vars["id"]
	var human Human
	db.First(&human, id)
	err := json.NewDecoder(request.Body).Decode(&human)
	if err != nil {
		log.Println(err)

	}
	db.Save(&human)
	err = json.NewEncoder(writer).Encode(human)
	if err != nil {
		log.Println(err)

	}
}

func deleteHuman(writer http.ResponseWriter, request *http.Request) {
	vars := mux.Vars(request)
	id := vars["id"]
	db.Delete(&Human{}, id)
	_, err := fmt.Fprintf(writer, "Human with ID = %s has been deleted", id)
	if err != nil {
		log.Println(err)

	}

}

func main() {
	err := DBConnection()
	if err != nil {
		log.Fatal("Database connection error", err)
	}
	router := mux.NewRouter()

	router.HandleFunc("/humans/{id}", getHuman).Methods("GET")
	router.HandleFunc("/humans", createHuman).Methods("POST")
	router.HandleFunc("/humans/{id}", updateHuman).Methods("PUT")
	router.HandleFunc("/humans/{id}", deleteHuman).Methods("DELETE")

	log.Fatal(http.ListenAndServe(":8080", router))
}