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[#1657] Reorganise the manual (146 / 176)

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Lukas Eder 2012-08-25 15:07:15 +02:00
parent 8b605c86b5
commit 570415d333
1 changed files with 65 additions and 2 deletions
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67
jOOQ-website/src/main/resources/manual-2.5.xml
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@ -6357,12 +6357,75 @@ for (BookRecord book : create.fetch(BOOK, BOOK.PUBLISHED_IN.equal(1948))) {
<section id="navigation-methods">
<title>Navigation methods</title>
<content></content>
<content>
<h3>Generated foreign key navigation methods</h3>
<p>
When using jOOQ's <reference id="code-generation" title="code generator"/> along with its <reference id="codegen-records" title="record generation capabilities"/>, generated records can have navigation methods contained in them, if properly <reference id="codegen-advanced" title="configured"/>. These navigation methods allow for "navigating" inbound or outbound foreign key references by executing an appropriate query. An example is given here:
</p>
<code-pair>
<sql><![CDATA[CREATE TABLE book (
AUTHOR_ID NUMBER(7) NOT NULL,
-- [...]
FOREIGN KEY (AUTHOR_ID) REFERENCES author(ID)
)]]></sql>
<java><![CDATA[BookRecord book = create.fetch(BOOK, BOOK.ID.equal(5));
// Find the author of a book
AuthorRecord author = book.fetchAuthor();
// Find other books by that author
List<BookRecord> books = author.fetchBookList();]]></java>
</code-pair>
<p>
These methods are safe for use with several foreign keys referencing the same tables:
</p>
<code-pair>
<sql><![CDATA[CREATE TABLE book (
AUTHOR_ID NUMBER(7) NOT NULL,
CO_AUTHOR_ID NUMBER(7) NOT NULL,
-- [...]
FOREIGN KEY (AUTHOR_ID) REFERENCES author(ID),
FOREIGN KEY (CO_AUTHOR_ID) REFERENCES author(ID)
)]]></sql>
<java><![CDATA[BookRecord book = create.fetch(BOOK, BOOK.ID.equal(5));
// Find the author of a book
AuthorRecord author = book.fetchAuthorByAuthorId();
AuthorRecord coAuthor = book.fetchAuthorByCoAuthorId();
// Find other books by those authors
List<BookRecord> books = author.fetchBookListByAuthorId();
List<BookRecord> books = coAuthor.fetchBookListByCoAuthorId();]]></java>
</code-pair>
<p>
Note that, unlike in Hibernate, jOOQ's generated navigation methods will always lazy-fetch relevant records, without caching any results. In other words, every time you run such a fetch method, a new query will be issued.
</p>
<p>
These fetch methods only work on "attached" records. See the manual's section about <reference id="serializability" title="serializability"/> for some more insight on "attached" objects.
</p>
</content>
</section>
<section id="non-updatable-records">
<title>Non-updatable records</title>
<content></content>
<content>
<h3>Tables without UNIQUE keys, and updatability</h3>
<p>
Tables without UNIQUE keys are considered non-updatable by jOOQ, as jOOQ has no way of uniquely identifying such a record within the database. If you're using jOOQ's <reference id="code-generation" title="code generator"/>, such tables will generate <reference class="org.jooq.TableRecord"/> classes, instead of <reference class="org.jooq.UpdatableRecord"/> classes. When you fetch <reference id="record-vs-tablerecord" title="typed records"/> from such a table, the returned records will not allow for calling any of the <reference id="crud-with-updatablerecords" title="store(), refresh(), delete()"/> methods.
</p>
<p>
Note, that some databases use internal rowid or object-id values to identify such records. jOOQ does not support these vendor-specific record meta-data.
</p>
</content>
</section>
<section id="optimistic-locking">