Working with DB datetime/date columns in Go

This post shows how to work with DATETIME/DATE columns in DB and use Go standard time.Time avoiding manual string parsing. This article contains examples using 2 packages: database/sql and github.com/go-sql-driver/mysql.

Retrieve nullable time field using NullTime type

MySQL, PostgreSQL drivers in Go provide this nullable type which represents a time.Time that may be NULL. NullTime implements the Scanner interface so it can be used as a scan destination:

var nt mysql.NullTime
err := db.QueryRow("SELECT time FROM foo WHERE id = ?", id).Scan(&nt)

if nt.Valid {
   // use nt.Time
} else {
   // NULL value
}

Use parseTime=true

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.

db, err := sql.Open("mysql", "root:@/?parseTime=true")

var myTime time.Time

db.QueryRow("SELECT current_timestamp()").Scan(&myTime)

fmt.Println(myTime.Format(time.RFC3339))

It doesn’t work with TIME column type

Notice that this doesn’t work with current_time. If you must use current_time you’ll need to do the parsing by yourself.