hoge.rb

    statement = db.prepare('SELECT m.id, m.created_at, m.content,' <<
                           'u.id as uid, u.avatar_icon, u.display_name, u.name' <<
                           'FROM message m LEFT JOIN user u ON u.id = m.user_id' <<
                           'WHERE m.id > ? AND channel_id = ? ORDER BY m.id DESC LIMIT 100')
    rows = statement.execute(last_message_id, channel_id).to_a
    response = rows.map do |row|
        {
            id: row['id'],
            date: row['created_at'].strftime("%Y/%m/%d %H:%M:%S"),
            content: row['content'],
            user: {
                id: row['uid'],
                display_name: row['display_name'],
                name:  row['name'],
                avatar_icon:  row['avatar_icon'],
            }

        }
    end.reverse!