dumps.go

package main

import (
	"database/sql"
	"fmt"
	"flag"

	_ "github.com/go-sql-driver/mysql"
)

type User struct {
	ID          int
	Email       string
	AccountName string
	NickName    string
}

type Profile struct {
	UserID    int
	FirstName string
	LastName  string
	Sex       string
	Birthday  string
	Pref      string
	Updated   string
}

var (
	db          *sql.DB
	userStmt    *sql.Stmt
	profileStmt *sql.Stmt
	dumpType = flag.Int("dump", 1, "dump type 1 = user, 2 = profile")
)

func init() {
	var err error
	db, err = sql.Open("mysql", "root:@/isucon5q")
	if err != nil {
		panic(err)
	}
	userStmt, err = db.Prepare(
		`SELECT id, email, account_name, nick_name FROM users`,
	)
	if err != nil {
		panic(err)
	}
	profileStmt, err = db.Prepare(
		`SELECT user_id, first_name, last_name, sex, birthday, pref, updated_at FROM profiles`,
	)
	if err != nil {
		panic(err)
	}
}

func main() {
	flag.Parse()
	if dumpType == 1 {
		rows, err := userStmt.Query()
		if err != nil {
			panic(err)
		}
		defer rows.Close()
		for rows.Next() {
			user := User{}
			err = rows.Scan(
				&user.ID,
				&user.Email,
				&user.AccountName,
				&user.NickName,
			)
			if err != nil {
				panic(err)
			}
			fmt.Printf(
				"%s\t%s\t%s\t%s\n",
				user.ID,
				user.Email,
				user.AccountName,
				user.NickName,
			)
		}
	} else {
		rows, err := profileStmt.Query()
		if err != nil {
			panic(err)
		}
		defer rows.Close()
		for rows.Next() {
			profile := Profile{}
			err = rows.Scan(
				&profile.UserID,
				&profile.FirstName,
				&profile.LastName,
				&profile.Sex,
				&profile.Birthday,
				&profile.Pref,
				&profile.Updated,
			)
			if err != nil {
				panic(err)
			}
			fmt.Printf(
				"%s\t%s\t%s\t%s\t%s\t%s\t%s\n",
				profile.UserID,
				profile.FirstName,
				profile.LastName,
				profile.Sex,
				profile.Birthday,
				profile.Pref,
				profile.Updated,
			)
		}
	}
}