Here’s a quick snippet you can use to create a custom type that maps an UUID to a Binary(16) representation in MySQL.

I assume this is not present in gofrs/uuid since it’s database specific, but having NullUUID available is an easy ‘inspiration’ opportunity ;).

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import (
	"database/sql/driver"

	"github.com/gofrs/uuid/v5"
)

type NullBinaryUUID struct {
	UUID  uuid.UUID
	Valid bool // Valid is true if UUID is not NULL
}

// Value implements the driver.Valuer interface.
func (u NullBinaryUUID) Value() (driver.Value, error) {
	if !u.Valid {
		return nil, nil
	}

	// Delegate to UUID Value function
	return u.UUID.Bytes(), nil
}

// Scan implements the sql.Scanner interface.
func (u *NullBinaryUUID) Scan(src interface{}) error {
	if src == nil {
		u.UUID, u.Valid = uuid.UUID{}, false
		return nil
	}

	// Delegate to UUID Scan function
	u.Valid = true
	return u.UUID.Scan(src)
}