CODEWITHSUNDEEP
mysqldatabasego
Caffeinatedwolf
Caffeinatedwolf

Reputation: 1317

How to parse time from database

I am using golang and I am trying to read time from mysql and I am getting the following error.

var my_time time.Time
rows, err := db.Query("SELECT current_time FROM table")
err := rows.Scan(&my_time)

The error I am getting is 

 unsupported driver -> Scan pair: []uint8 -> *time.Time

How can I fix this?

Upvotes: 39

Views: 43187

Answers (1)

Not_a_Golfer
Not_a_Golfer

Reputation: 49283

Assuming you're using the go-sql-driver/mysql you can ask the driver to scan DATE and DATETIME automatically to time.Time, by adding parseTime=true to your connection string.

See https://github.com/go-sql-driver/mysql#timetime-support

Example code:

db, err := sql.Open("mysql", "root:@/?parseTime=true")
if err != nil {
    panic(err.Error()) // Just for example purpose. You should use proper error handling instead of panic
}
defer db.Close()

var myTime time.Time
rows, err := db.Query("SELECT current_timestamp()")

if rows.Next() {
    if err = rows.Scan(&myTime); err != nil {
        panic(err)
    }
}

fmt.Println(myTime)

Notice that this works with current_timestamp but not with current_time. If you must use current_time you'll need to do the parsing youself.

This is how you do custom parsing:

First, we define a custom type wrapping []byte, that will automatically parse time values:

type rawTime []byte

func (t rawTime) Time() (time.Time, error) {
    return time.Parse("15:04:05", string(t))
}

And in the scanning code we just do this:

var myTime rawTime
rows, err := db.Query("SELECT current_time()")

if rows.Next() {
    if err = rows.Scan(&myTime); err != nil {
        panic(err)
    }
}

fmt.Println(myTime.Time())

Upvotes: 90

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