5. gin集成Gorm - 技术栈

文章目录

一：连接DB
二：增删改查
三：使用PostMan测试

代码地址：https://gitee.com/lymgoforIT/golang-trick/tree/master/24-gin-learning

本节主要介绍如何使用gin集成gorm，并完成用户的创建、修改、删除、查询等功能

本节主要是做最基本的连接和增删改查演示，具体使用细节可以查看官方文档：https://gorm.io/zh_CN/docs/

一：连接DB

引入gorm与mysql驱动

go 复制代码

go get gorm.io/gorm
go get gorm.io/driver/mysql

定义model和requst

go 复制代码

type User struct {
	gorm.Model
	Name  string `json:"name" binding:"required"`
	Email string `json:"email" binding:"required"`
}

type UpdateUserInput struct {
	Name  string `json:"name"`
	Email string `json:"email"`
}

注：

binding tag为gin中绑定参数时的校验，将入参绑定到user对象时，对应字段为必传项
上面User和UpdateUserInput看上去拥有的字段差不多，为什么还定义了两个结构体呢？原因是User为与DB交互的model，UpdateUserInput为接口的request，实际工作中model和request会有很多相似的字段，但一般不会完全一样，如request中可能会带有size，page等用于分页查询的字段。

连接DB

go 复制代码

package main

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

type User struct {
	gorm.Model
	Name  string `json:"name" binding:"required"`
	Email string `json:"email" binding:"required"`
}

type UpdateUserInput struct {
	Name  string `json:"name"`
	Email string `json:"email"`
}

func main() {

	dsn := "root:root@(127.0.0.1:3306)/test?charset=utf8mb4&parseTime=true&loc=Local"
	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		panic(any("failed to connect to db"))
	}

	// 建表
	err = db.AutoMigrate(&User{})
	if err != nil {
		panic(any("create table err"))
	}
}

运行上述代码后，可看到DB中创建了users表，当model没有实现Table方法时，表名默认为在model结构体名字后面加s,因此此处model名为User，所以表名是users

二：增删改查

代码如：

go 复制代码

package main

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

type User struct {
	gorm.Model
	Name  string `json:"name" binding:"required"`
	Email string `json:"email" binding:"required"`
}

type UpdateUserInput struct {
	Name  string `json:"name"`
	Email string `json:"email"`
}

func main() {

	dsn := "root:root@(127.0.0.1:3306)/test?charset=utf8mb4&parseTime=true&loc=Local"
	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		panic(any("failed to connect to db"))
	}

	// 建表
	err = db.AutoMigrate(&User{})
	if err != nil {
		panic(any("create table err"))
	}

	r := gin.Default()

	r.GET("/ping", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"message": "pong",
		})
	})

	// Get /users
	r.GET("/users", func(c *gin.Context) {
		var users []User
		err := db.Find(&users).Error
		if err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to find users",
			})
			log.Println("Failed to find users")
			return
		}
		c.JSON(http.StatusOK, gin.H{"data": users})
	})

	// Post /users
	r.POST("/users", func(c *gin.Context) {
		var input User
		if err := c.ShouldBindJSON(&input); err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": err.Error(),
			})
			return
		}

		if err := db.Create(&input).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to create users",
			})
			log.Println("Failed to create users")
			return
		}
		c.JSON(http.StatusOK, gin.H{"data": input})
	})

	// Put /users
	r.PUT("/users/:id", func(c *gin.Context) {
		var input UpdateUserInput
		if err := c.ShouldBindJSON(&input); err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "invalid params",
			})
			log.Println("invalid params")
			return
		}

		id := c.Param("id")
		var user User
		if err := db.Where("id = ?", id).Find(&user).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to Find user",
			})
			log.Println("Failed to Find user")
			return
		}
		if input.Name != "" {
			user.Name = input.Name
		}
		if input.Email != "" {
			user.Email = input.Email
		}

		if err := db.Save(&user).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to save user",
			})
			log.Println("Failed to save user")
			return
		}
		c.JSON(http.StatusOK, gin.H{"data": user})
	})

	// Delete /users
	r.DELETE("/users/:id", func(c *gin.Context) {
		id := c.Param("id")
		var user User
		if err := db.First(&user, id).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to Find user",
			})
			log.Println("Failed to Find user")
			return
		}
		if err := db.Delete(&user, id).Error; err != nil {
			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to delete user",
			})
			log.Println("Failed to delete user")
			return
		}

		c.JSON(http.StatusOK, gin.H{"data": "Delete user " + id})
	})

	r.Run(":8080")
}