go gin gorm操作db

module hellogin

go 1.15

require (
  github.com/gin-gonic/gin v1.6.3
  github.com/go-sql-driver/mysql v1.5.0
  github.com/jinzhu/gorm v1.9.16
)

package main

import (
  "fmt"
  "github.com/gin-gonic/gin"
  _ "github.com/go-sql-driver/mysql"
  "github.com/jinzhu/gorm"
  "log"
  "net/http"
)

type User struct {
  gorm.Model
  Name      string `gorm:"type:varchar(20);not null"`
  Telephone string `gorm:"varchar(20);not null;unique"`
  Password  string `gorm:"size:255;not null"`
}

var (
  db  *gorm.DB
  err error
)

func main() {
  initDB()
  defer db.Close()

  r := gin.Default()

  r.GET("/ping", func(c *gin.Context) {
    c.JSON(200, gin.H{
      "message": "pong",
    })
  })

  // 路由配置
  r.POST("/user/create", CreateUser)
  r.DELETE("/user/:id", DeleteUser)
  r.GET("/users", ListUser)
  r.GET("/user/:id", GetUser)
  r.PUT("/user/:id", UpdateUser)

  r.Run()
}

// 数据库连接
func initDB() *gorm.DB {
  driverName := "mysql"
  host := "127.0.0.1"
  port := "3306"
  database := "test"
  username := "root"
  password := "root"
  charset := "utf8"

  args := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=%s&parseTime=true",
    username,
    password,
    host,
    port,
    database,
    charset,
  )

  db, err = gorm.Open(driverName, args)
  if err != nil {
    panic("failed to connect database,err:" + err.Error())
  }

  db.DB().SetMaxIdleConns(10)
  db.DB().SetMaxOpenConns(100)

  // 全局禁用表名复数
  db.SingularTable(true) // 如果设置为true,`User`的默认表名为`user`,使用`TableName`设置的表名不受影响

  // 一般不会直接用CreateTable创建表
  // 检查模型`User`表是否存在，否则为模型`User`创建表
  if !db.HasTable(&User{}) {
    if err := db.Set("gorm:table_options", "ENGINE=InnoDB").AutoMigrate(&User{}).Error; err != nil {
      panic(err)
    }
  }

  return db
}

// 创建用户
func CreateUser(c *gin.Context) {
  var user User
  c.BindJSON(&user) // 使用bindJson填充数据

  // db.Create(&user)  // 创建对象
  // c.JSON(http.StatusOK, &user)  // 返回页面

  if user.Name != "" && user.Password != "" {
    //
    if err := db.Create(&user).Error; err != nil {
      fmt.Println("error 了")
      c.JSON(400, gin.H{"error": err.Error()})
      return
    }

    c.JSON(http.StatusOK, gin.H{
      "code":    20000,
      "message": "success",
      "data":    &user,
    })
  } else {
    c.JSON(422, gin.H{"error": "Fields are empty"})
  }
}

// 删除用户
func DeleteUser(c *gin.Context) {
  id := c.Params.ByName("id")

  log.Println("id:", id)

  if err := db.Where(&User{Name: id}).Delete(User{}).Error; err != nil {
    c.JSON(500, gin.H{
      "msg":   "删除失败",
      "error": err.Error(),
    })
  }

  c.JSON(http.StatusOK, gin.H{
    "msg":  "删除成功",
    "data": "User# " + id + " deleted!",
  })

  // 2
  //var user User
  //db.First(&user, id)
  //if user.Name {
  //  db.Delete(&user)
  //  c.JSON(http.StatusOK, gin.H{
  //    "success": "User# " + id + " deleted!",
  //  })
  //} else{
  //  c.JSON(404, gin.H{
  //    "error": "User not found",
  //  })
  //}
}

// 列出所有用户
func ListUser(c *gin.Context) {
  var user []User
  db.Find(&user)
  c.JSON(http.StatusOK, &user) //限制查找前line行
}

// 列出单个用户
func GetUser(c *gin.Context) {
  var user User
  id := c.Params.ByName("id")
  err := db.First(&user, id).Error
  if err != nil {
    c.AbortWithStatus(404)
    fmt.Println(err.Error())
  } else {
    c.JSON(http.StatusOK, &user)
  }
}

// 更新用户
func UpdateUser(c *gin.Context) {
  var user User
  id := c.Params.ByName("id")

  err := db.First(&user, id).Error
  if err != nil {
    c.AbortWithStatus(404)
    fmt.Println(err.Error())
  } else {
    c.BindJSON(&user)

    if err := db.Save(&user).Error; err != nil {
      c.JSON(http.StatusOK, gin.H{
        "message": err.Error(),
      }) // 返回页面
      return
    }

    // 提交修改
    c.JSON(http.StatusOK, &user) // 返回页面
  }
}