package main

import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"log"
)

var dataB *sql.DB

func initDataB() (err error) {
	dataB, err = sql.Open("mysql", "root:123456@tcp(43.143.245.135:3306)/wangaodev")
	if err != nil {
		log.Println(err)
		return err
	}
	err = dataB.Ping()
	if err != nil {
		log.Println(err)
		return err
	}
	log.Println("Successfully connected to mysql")
	dataB.SetMaxOpenConns(10)
	dataB.SetMaxIdleConns(5)
	return nil
}

type newUser struct {
	name   string
	level  string
	status int
}

func generateNewUser(name, level string, status int) *newUser {
	return &newUser{
		name:   name,
		level:  level,
		status: status,
	}
}

// 预处理方式插入多条数据
func prepareInsert() {
	sqlStr := `insert into user (name,level,status) values (?,?,?)`
	stmt, err := dataB.Prepare(sqlStr)
	if err != nil {
		log.Fatal("prepare failed:", err)
	}
	defer stmt.Close()
	//后续只需要拿到stmt去执行一些操作
	userData := []newUser{
		{name: "Alice", level: "中级", status: 1},
		{name: "Bob", level: "高级", status: 2},
		{name: "Charlie", level: "初级", status: 0},
	}
	//循环结构体切片执行
	var sum = 0
	for _, v := range userData {
		ret, err := stmt.Exec(v.name, v.level, v.status)
		if err != nil {
			return
		}
		n, _ := ret.RowsAffected()
		sum = sum + int(n)
	}
	fmt.Printf("%v rows has been affected", sum)

}

func main() {
	err := initDataB()
	if err != nil {
		return
	}
	prepareInsert()
}