本文讲述了如何使用Gin和xorm实现一个简单的RESTful风格的接口, 并进行CRUD操作;
源代码:
https://github.com/JasonkayZK/Go_Learn/tree/go-restful-xorm
使用Gin+xorm实现简单的CRUD
Model
本例以Pet模型为例，其模型定义如下：
models/pet.go
package models
import (
"time"
)
type (
Pet struct {
Id int `json:"id" binding:"required" form:"id"`
Name string `json:"name" xorm:"varchar(20)" binding:"required" form:"name"`
Age int `json:"age" binding:"required" form:"age"`
Photo string `json:"photo" xorm:"varchar(30)"`
Ctime time.Time `json:"created_at" xorm:"ctime"`
Utime time.Time `json:"updated_at" xorm:"utime"`
}
)对应的SQL如下
sql/schema.sql
USE `test`;
DROP TABLE IF EXISTS `pets`;
CREATE TABLE `pets`
(
`id` INT(10) AUTO_INCREMENT NOT NULL COMMENT '宠物编号',
`name` VARCHAR(20) NOT NULL COMMENT '宠物名称',
`age` TINYINT(3) NOT NULL COMMENT '宠物年龄',
`photo` VARCHAR(30) DEFAULT NULL COMMENT '宠物图片',
`ctime` DATETIME DEFAULT CURRENT_TIMESTAMP,
`utime` DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE = InnoDB,
DEFAULT CHARSET = utf8mb4 COMMENT ='宠物表';
INSERT INTO `pets` (ID, NAME, AGE)
VALUES (1, 'cat', '1');
INSERT INTO `pets` (ID, NAME, AGE)
VALUES (2, 'dog', '2');
INSERT INTO `pets` (ID, NAME, AGE)
VALUES (3, 'mouse', '3');Routing
在routing/web.go的routing方法中定义了路由:
...
type WebService struct{}
func (w *WebService) routing(db *xorm.Engine) {
petController := controller.PetController{DB: db}
r := gin.Default()
v1 := r.Group("/pets")
v1.GET("/", petController.Index)
v1.POST("/", petController.Create)
v1.GET("/:id", petController.Show)
v1.PUT("/:id", petController.Update)
v1.DELETE("/:id", petController.DeleteById)
err := r.Run()
if err != nil {
fmt.Printf("fail to start")
}
}API
和routing对应的，在controller/pet_controller.go中定义了具体API的实现:
package controller
import (
"fmt"
"go-restful-xorm/models"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
"github.com/go-xorm/xorm"
)
type PetController struct {
DB *xorm.Engine
}
func (p *PetController) Index(c *gin.Context) {
var pets []models.Pet
err := p.DB.Table("pets").Find(&pets)
if err != nil {
fmt.Printf("%v", err)
}
if len(pets) <= 0 {
c.JSON(404, gin.H{"status": 404, "message": "not found."})
return
}
c.JSON(200, gin.H{"status": 200, "data": pets})
}
func (p *PetController) Create(c *gin.Context) {
var pet models.Pet
fmt.Printf("Create id: %s\n", c.Param("id"))
if err := c.ShouldBind(&pet); err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
return
}
fmt.Printf("Insert data: %v\n", pet)
insert, err := p.DB.Table("pets").Insert(&pet)
if err != nil {
c.JSON(404, gin.H{"error": err.Error()})
return
}
if insert != 1 {
c.JSON(404, gin.H{"error": "Fail to insert, maybe exist?"})
}
c.JSON(200, gin.H{"status": 200, "message": "pet item created."})
}
func (p *PetController) Show(c *gin.Context) {
var pet models.Pet
has, err := p.DB.Table("pets").Where("id = ?", c.Param("id")).Get(&pet)
if err != nil {
c.JSON(404, gin.H{"status": 404, "message": "pet select error"})
return
}
if !has {
c.JSON(404, gin.H{"status": 404, "message": "pet not found"})
return
}
if pet.Id == 0 {
c.JSON(404, gin.H{"status": 404, "message": "pet not found"})
return
}
c.JSON(200, gin.H{"status": 200, "data": pet})
}
func (p *PetController) Update(c *gin.Context) {
petId, _ := strconv.Atoi(c.Param("id"))
petName := c.PostForm("name")
petAge, _ := strconv.Atoi(c.PostForm("age"))
fmt.Printf("Update id: %s\n", c.Param("id"))
res, err := p.DB.Exec("UPDATE `pets` SET `name` = ?, `age` = ? WHERE `id` = ?", petName, petAge, petId)
if err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
return
}
if affected, _ := res.RowsAffected(); affected != 1 {
c.JSON(404, gin.H{"status": 404, "message": "fail to update, maybe record not exist?"})
return
}
c.JSON(200, gin.H{"status": 200, "message": "pet data updated."})
}
func (p *PetController) DeleteById(c *gin.Context) {
res, err := p.DB.Exec("DELETE FROM `pets` WHERE `id` = ?", c.Param("id"))
if err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
return
}
if affected, _ := res.RowsAffected(); affected != 1 {
c.JSON(404, gin.H{"status": 404, "message": "fail to delete, maybe record not exist?"})
return
}
c.JSON(200, gin.H{"status": 200, "message": "pet data deleted."})
}ORM框架采用的是XORM
Config
在项目的根目录下使用config.json简单定义了数据库的相关配置;
项目启动时通过config/get_config.go加载相关的配置信息，并使用GetConfig方法获取相关配置；
package config
import (
"encoding/json"
"fmt"
"io/ioutil"
)
var (
appConfig map[string]string
)
func init() {
err := loadConfig()
if err != nil {
fmt.Printf("failed to load config")
}
}
func loadConfig() error {
appConfig = map[string]string{}
data, err := ioutil.ReadFile("config.json")
if err != nil {
return fmt.Errorf("failed to load config")
}
err = json.Unmarshal(data, &appConfig)
if err != nil {
return fmt.Errorf("failed to unmarshal config")
}
return nil
}
func GetConfig(key string) string {
if value, exist := appConfig[key]; exist {
return value
} else {
return "error"
}
}Deployment
在根目录下的server.go作为整个项目的入口;
package main
import (
"fmt"
"go-restful-xorm/routing"
)
func main() {
server := routing.WebService{}
server.Run()
fmt.Println("Server started!")
}server.go中调用了routing/web.go中的Run()方法，完成了创建SQL连接Engine，并对8080（默认）端口对应路由进行监听：
......
func (w *WebService) Run() {
engine, err := xorm.NewEngine(
"mysql",
fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8",
c.GetConfig("dbusername"),
c.GetConfig("dbpassword"),
c.GetConfig("dbhost"),
c.GetConfig("dbport"),
c.GetConfig("dbname")))
if err != nil {
fmt.Printf("fail to connect database")
}
//日志打印SQL
engine.ShowSQL(true)
//设置连接池的空闲数大小
engine.SetMaxIdleConns(5)
//设置最大打开连接数
engine.SetMaxOpenConns(15)
//名称映射规则主要负责结构体名称到表名和结构体field到表字段的名称映射
engine.SetTableMapper(core.SnakeMapper{})
w.routing(engine)
}Test
可以使用Postman或其他测试工具测试；
附录
源代码:
https://github.com/JasonkayZK/Go_Learn/tree/go-restful-xorm
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