====== 検索ワード ======

===== 取得 =====

  * 大文字小文字を区別せずソート

  select distinct search from books order by lower(search);

===== メンテ用 =====

  * 小文字へ変換

  update books set search = lower(search)

  * 文字列変換

  update books set url=replace(url, "word_from", "word_to");