代码语言：txt复制
package main
import (
"fmt"
"math/rand"
"strconv"
"time"
_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
)
type City struct {
CityId int64 `gorm:"column:city_id"`
CityName string `gorm: "column:city_name"`
CityIntroduce string `gorm:"column:city_introduce"`
}
func main() {
db := initDB()
defer db.Close()
var id int64 = 2222
//查
var a_city City
db.Table("city").Where("city_id=?", id).First(&a_city)
fmt.Println("%#T", a_city)
if a_city.CityId == 0 {
//增
city1 := City{CityId: id, CityName: "paris", CityIntroduce: "good city"}
db.Table("city").Create(&city1)
}
//改
random_data := strconv.Itoa(rand.Int())
new_city_introduce := "good city:" random_data
db.Table("city").Where("city_id=?", id).Update("city_introduce", new_city_introduce)
//删
db.Table("city").Where("city_id=?", id).Delete(&City{})
}
func initDB() *gorm.DB {
dsn := "root:123456@tcp(127.0.0.1:3306)/test?charset=utf8mb4"
db, err := gorm.Open("mysql", dsn)
if err != nil {
panic(err)
}
db.DB().SetMaxOpenConns(50)
db.DB().SetMaxIdleConns(2)
db.DB().SetConnMaxLifetime(time.Second * 300)
if err = db.DB().Ping(); err != nil {
panic(err)
}
return db
}
