[Go] RESTFul API 구현

주제

1. https://gin-gonic.github.io/gin/

2. http://jinzhu.me/gorm/

3. gorm, gin-gonic을 이용하여 실제 RESTFul API를 구현

$ go get github.com/jinzhu/gorm

$ go get github.com/gin-gonic/gin

과제

CREATE SEQUENCE seq_user

INCREMENT 1

MINVALUE 1

MAXVALUE 9223372036854775807

START 1

CACHE 1;

CREATE TABLE "user"

(

user_seq_no bigint NOT NULL DEFAULT nextval('seq_user'::regclass), 

name character varying(10) NOT NULL,

email character varying(30) NOT NULL,

age smallint NOT NULL,

birthday date NOT NULL,

mobile character varying(20) NOT NULL,

insert_datetime timestamp without time zone NOT NULL,

CONSTRAINT pk_user PRIMARY KEY (user_seq_no)

)

WITH (

OIDS=FALSE

);

COMMENT ON COLUMN user.user_seq_no IS '시퀀스';

COMMENT ON COLUMN user.name IS '회원 이름';

COMMENT ON COLUMN user.email IS '회원 이메일';

COMMENT ON COLUMN user.age IS '나이';

COMMENT ON COLUMN user.birthday IS '생년월일';

COMMENT ON COLUMN user.mobile IS '핸드폰 번호';

COMMENT ON COLUMN user.insert_datetime IS '등록일시';

코드

리팩토링을 하지 않은 코드이므로 감안하여 보길 바랍니다.

package main

import (
	_ "database/sql"
	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/postgres"
	"github.com/gin-gonic/gin"
	"log"
	"time"
	"net/http"
	"strconv"
	"fmt"
)

type User struct {
				  // 컬럼명은 대문자여야 한다
	User_seq_no     uint64 `gorm:"primary_key"`
	Name            string
	Email           string
	Age             int
	Birthday        string
	Mobile          string
	Insert_datetime time.Time // time.Time import "time"
}

func (User) TableName() string {
	// set table name
	return "t_user"
}

func main() {
	// set api router
	router := gin.Default()

	router.GET("/users", get_users)
	router.POST("/users", post_users)
	router.PUT("/users/:pk", put_users)
	router.DELETE("/users/:pk", delete_users)

	router.Run(":8000")

}

func get_users (c *gin.Context) {
	// set database
	db, err := gorm.Open("postgres", "user=_user_ password=_password_ dbname=golang sslmode=disable")
	if err != nil {
		log.Fatal("faild to connect database")
	}
	defer db.Close()

	// get users
	var users []User
	db.Find(&users)

	c.JSON(http.StatusOK, gin.H{
		"status": http.StatusOK,
		"data": &users,
		"message": nil,
	})
}

func post_users(c *gin.Context) {
	// set database
	db, err := gorm.Open("postgres", "user=_user_ password=_password_ dbname=golang sslmode=disable")
	if err != nil {
		log.Fatal("faild to connect database")
	}
	defer db.Close()

	name := c.PostForm("name")
	email := c.PostForm("email")
	age, _ := strconv.Atoi(c.PostForm("age"))
	birthday := c.PostForm("birthday")
	mobile := c.PostForm("mobile")

	if name == "" || email == "" || age == 0 || mobile == "" {
		c.JSON(http.StatusBadRequest, gin.H{
			"status": http.StatusBadRequest,
			"data": nil,
			"message": "Parameter is not valid.",
		})
	} else {
		user := User{
			Name:            name,
			Email:           email,
			Age:             age,
			Birthday:        birthday,
			Mobile:          mobile,
			Insert_datetime: time.Now(),
		}

		if err := db.Create(&user).Error; err != nil {
			fmt.Print(err)
			c.JSON(http.StatusBadRequest, gin.H{
				"status": http.StatusBadRequest,
				"data": nil,
				"message": err,
			})
		} else {
			// 마지막 값을 가져와 반환한다
			db.Last(&user)
			c.JSON(http.StatusOK, gin.H{
				"status": http.StatusOK,
				"data": user,
				"message": nil,
			})
		}
	}

}

func put_users (c *gin.Context) {
	// set database
	db, err := gorm.Open("postgres", "user=_user_ password=_password_ dbname=golang sslmode=disable")
	if err != nil {
		log.Fatal("faild to connect database")
	}
	defer db.Close()

	pk, _ := strconv.ParseUint(c.Param("pk"), 10, 32)

	name := c.PostForm("name")
	email := c.PostForm("email")
	age, _ := strconv.Atoi(c.PostForm("age"))
	birthday := c.PostForm("birthday")
	mobile := c.PostForm("mobile")

	user := User{
		Name: name,
		Email: email,
		Age: age,
		Birthday: birthday,
		Mobile: mobile,
	}

	if err := db.Where(User{User_seq_no: pk}).Assign(user).FirstOrCreate(&user).Error; err != nil {
		fmt.Print(err)
		c.JSON(http.StatusBadRequest, gin.H{
			"status": http.StatusBadRequest,
			"data": nil,
			"message": err,
		})
	} else {
		c.JSON(http.StatusOK, gin.H{
			"status": http.StatusOK,
			"data": user,
			"message": nil,
		})
	}
}

func delete_users (c *gin.Context) {
	// set database
	db, err := gorm.Open("postgres", "user=_user_ password=_password_ dbname=golang sslmode=disable")
	if err != nil {
		log.Fatal("faild to connect database")
	}
	defer db.Close()

	pk, _ := strconv.ParseUint(c.Param("pk"), 10, 32)

	db.Where("user_seq_no = ?", pk).Delete(&User{})
	c.JSON(http.StatusOK, gin.H{
		"status": http.StatusOK,
		"data": nil,
		"message": "Delete Success.",
	})
}