|The jOOQ User Manual. Multiple Pages : SQL execution : Fetching : Record vs. TableRecord||previous : next|
jOOQ understands that SQL is much more expressive than Java, when it comes to the declarative typing of table expressions. As a declarative language, SQL allows for creating ad-hoc row value expressions (records with indexed columns, or tuples) and records (records with named columns). In Java, this is not possible to the same extent.
Yet, still, sometimes you wish to use strongly typed records, when you know that you're selecting only from a single table:
When fetching data only from a single table, the table expression's type is known to jOOQ if you use jOOQ's code generator to generate TableRecords for your database tables. In order to fetch such strongly typed records, you will have to use the simple select API:
// Use the selectFrom() method: BookRecord book = create.selectFrom(BOOK).where(BOOK.ID.eq(1)).fetchOne(); // Typesafe field access is now possible: System.out.println("Title : " + book.getTitle()); System.out.println("Published in: " + book.getPublishedIn());
When you use the DSLContext.selectFrom() method, jOOQ will return the record type supplied with the argument table. Beware though, that you will no longer be able to use any clause that modifies the type of your table expression. This includes:
Sometimes, you may want to explicitly select only a subset of your columns, but still use strongly typed records. Alternatively, you may want to join a one-to-one relationship and receive the two individual strongly typed records after the join.
// Join two tables Record record = create.select() .from(BOOK) .join(AUTHOR).on(BOOK.AUTHOR_ID.eq(AUTHOR.ID)) .where(BOOK.ID.eq(1)) .fetchOne(); // "extract" the two individual strongly typed TableRecord types from the denormalised Record: BookRecord book = record.into(BOOK); AuthorRecord author = record.into(AUTHOR); // Typesafe field access is now possible: System.out.println("Title : " + book.getTitle()); System.out.println("Published in: " + book.getPublishedIn()); System.out.println("Author : " + author.getFirstName() + " " + author.getLastName();