[Go]生成CSV

package main

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

var db *sql.DB

type User struct {
	Uid      int
	Name     string
	Phone    string
	Email    string
	Password string
}

var u User

//初始化
func init() {
	db, _ = sql.Open("mysql",
		"root:a123456@tcp(127.0.0.1:3306)/xxx")
}

func main() {
	//設定檔名
	filename := "./exportUsers.csv"

	//取得數據
	users := queryMultiRow()
	//定義一個二維數組
	column := [][]string{{"手機號碼", "用戶UID", "Email", "用戶名"}}
	for _, u := range users {
		str := []string{}
		str = append(str, u.Phone)
		str = append(str, strconv.Itoa(u.Uid))
		str = append(str, u.Email)
		str = append(str, u.Name)
		column = append(column, str)
	}
	//匯出
	ExportCsv(filename, column)
}

//匯出csv文件
func ExportCsv(filePath string, data [][]string) {
	fp, err := os.Create(filePath)
	if err != nil {
		log.Fatalf("建立檔案["+filePath+"]失敗,%v", err)
		return
	}
	defer fp.Close()
	//寫入UTF-8 BOM
	fp.WriteString("\xEF\xBB\xBF")
	//建立一個新的寫入檔案流
	w := csv.NewWriter(fp)         
	w.WriteAll(data)
	w.Flush()
}

//查詢多條數據
func queryMultiRow() ([]User) {
	rows, err := db.Query("select uid,name,phone,email from `user` where uid > ?", 0)
	if err != nil {
		fmt.Printf("query failed, err:%v\n", err)
		return nil
	}
	defer rows.Close()
	
	users := []User{}
	for rows.Next() {
		err := rows.Scan(&u.Uid, &u.Name, &u.Phone, &u.Email)
		users = append(users, u)
		if err != nil {
			fmt.Printf("scan failed, err:%v\n", err)
			return nil
		}
	}
	return users
}