名前付きstring型をScanしたい時（database.sql.Scanner）

package main

import "fmt"

type Animal string

const (
	Cat Animal = "cat"
	Dog Animal = "dog"
)

func (a *Animal) Scan(src interface{}) error {
	str := fmt.Sprintf("%s", src)
	*a = Animal(str)
	return nil
}

func main() {
	var animal Animal
	animal.Scan("cat")
	fmt.Println(animal)

	fmt.Println(animal.Scan("monkey"))
}

run:

cat
<nil>

Playground

よく忘れるので・・・

参考

• http://stackoverflow.com/questions/24264485/saving-enumerated-values-to-a-database