January 2021
Intermediate
240 pages
5h 32m
Japanese
Content preview from 図解まるわかり データベースのしくみ
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24
1-6
データベースを操作するための
命令文
SQLはです。SQL言語のコマン
ドをデータベース管理システムに送ると、その内容に従ってデータベース
を操作することができます（図1-11）。また、SQLは規格化された言語で
す。1-5で紹介したようにデータベース管理システムにはたくさんの種
類がありますが、多くのシステムで共通のSQL言語を使うことができま
す。SQL言語さえ覚えておけば、代表的なデータベース管理システムは同
様のコマンドで操作することができるというわけです。
また、SQLにはデータベースと対話形式でやりとりするという特徴があ
ります。例えば、新しいデータベースを作成するためのSQLコマンドを
データベース管理システムに送ると、それを受け取ったデータベース管理
システムは命令に従ってデータベースを操作し、処理が終わると実行結果
を返します。
このようにSQLでデータベースを操作するときは、命令を送り、その
結果が返ってくる、という流れをデータベース管理システムと1 対 1 で繰
り返すことになります（図1-12）。
SQLを使うと、データベースに関するさまざまな操作を行うことができ
ます。具体的なSQLの使い方は第3 章で解説していきますが、おおまかに
は以下のようなものがあります。
新しいデータベースやテーブルの作成・削除
データの追加・編集・削除
データの検索
データにアクセスできるユーザー権限の設定
SQLは対話形式でやりとりする
SQLでで ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.