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Convert time.Time to string Ask Question

tag-icon • tag-icon string go datetime time
Convert time.Time to string Ask Question

I'm trying to add some values from my database to a []string in Go. Some of these are timestamps.

I get the error:

cannot use U.Created_date (type time.Time) as type string in array element

Can I convert time.Time to string?

type UsersSession struct {
    Userid int
    Timestamp time.Time
    Created_date time.Time
}

type Users struct {
    Name string
    Email string
    Country string
    Created_date time.Time
    Id int
    Hash string
    IP string
}

var usersArray = [][]string{}

rows, err := db.Query("SELECT u.id, u.hash, u.name, u.email, u.country, u.IP, u.created_date, us.timestamp, us.created_date FROM usersSession AS us LEFT JOIN users AS u ON u.id = us.userid WHERE us.timestamp + interval 30 minute >= now()")

U := Users{}
US := UsersSession{}

for rows.Next() {
    err = rows.Scan(&U.Id, &U.Hash, &U.Name, &U.Email, &U.Country, &U.IP, &U.Created_date, &US.Timestamp, &US.Created_date)
    checkErr(err)

    userid_string := strconv.Itoa(U.Id)
    user := []string{userid_string, U.Hash, U.Name, U.Email, U.Country, U.IP, U.Created_date, US.Timestamp, US.Created_date}
    // -------------
    // ^ this is where the error occurs
    // cannot use U.Created_date (type time.Time) as type string in array element (for US.Created_date and US.Timestamp aswell)
    // -------------

    usersArray = append(usersArray, user)
    log.Print("usersArray: ", usersArray)
}

ベストアンサー1

You can use the Time.String() method to convert a time.Time to a string. This uses the format string "2006-01-02 15:04:05.999999999 -0700 MST".

If you need other custom format, you can use Time.Format(). For example to get the timestamp in the format of yyyy-MM-dd HH:mm:ss use the format string "2006-01-02 15:04:05".

Example:

t := time.Now()
fmt.Println(t.String())
fmt.Println(t.Format("2006-01-02 15:04:05"))

Output (try it on the Go Playground):

2009-11-10 23:00:00 +0000 UTC
2009-11-10 23:00:00

Note: time on the Go Playground is always set to the value seen above. Run it locally to see current date/time.

Also note that using Time.Format(), as the layout string you always have to pass the same time –called the reference time– formatted in a way you want the result to be formatted. This is documented at Time.Format():

フォーマットは、レイアウトに従ってフォーマットされた時間値のテキスト表現を返します。レイアウトは、定義された参照時間を示すことによってフォーマットを定義します。

Mon Jan 2 15:04:05 -0700 MST 2006

値であれば、次のように表示されます。これは、望ましい出力の例として機能します。同じ表示ルールが時間値にも適用されます。

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