May 2024
Intermediate to advanced
752 pages
24h
Japanese
Content preview from Spring徹底入門 第2版 Spring FrameworkによるJavaアプリケーション開発
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.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.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.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.
496
SpringDataJPA
10
場合は、関連を定義するアノテーションの
fetch
属性に
FetchType
を設定します。以下に、関 連
Entity
である
equipments
を
Eager
フェッチで読み込むための設定例を示します。
フェッチ方法の指定例
@OneToMany
(mappedBy = "room", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
private List
<Equipment>
equipments;
JPQL（Java Persistence Query Language）
EntityManager
が用意する
API
（メソッド）を利用することで、主キー指定でデータベースのレコードを参
照・更新する方法を紹介しました。しかし一般的なアプリケーション開発では、主キー指定以外でのデータ
ベースアクセスが不可欠です。たとえば、一覧や検索結果の表示、一括更新などの処理が挙げられます。
JPA
では、主キー指定以外でのデータベースへアクセスを行なう方法も用意されています。
SQL
のような 柔 軟 なクエ
リを記述する方法が以下のように複数用意されています。
表
10.6
JPQL
のクエリ記述方法
方法 説明
JPQL（JavaPersistence
QueryLanguage）
SQLライクなJPA独自のクエリ言語を記述することで
Entity
の取得や更新を行なう方法。SQL
との大きな違いは、SQL の入出力がテーブルやその列や行で表 ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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.