Getting error message
NestedThrowablesStackTrace:
java.lang.IllegalArgumentException: can't operate on multiple entity
groups in a single transaction. found both Element {
type: "Book"
id: 2
}
and Element {
type: "Book"
id: 4
}
fails on the line
BookService : book.getPage(); as each book is in a separate
entity group
but why does it not fail on
Book book = bookmark.getBook();? as each bookmark is also in a
separate entity group.
@Test
public void listTwoBooksBySingleUser() {
User user = new User("[email protected]", "test auth domain",
"1234");
userService.save(user);
Book book1 = new Book();
book1.setTitle("test book title 1");
bookService.save(book1);
Book book2 = new Book();
book2.setTitle("test book title 2");
bookService.save(book2);
bookService.createBookmarkForUser(book1, user);
bookService.createBookmarkForUser(book2, user);
List<Book> books = bookService.listByUser(user);
assertEquals(2,books.size());
assertEquals("test book title 1", books.get(0).getTitle());
assertEquals("test book title 2", books.get(1).getTitle());
}
public class BookService {
public List<Book> listByUser(User user) {
Query query = em.createQuery("SELECT bm FROM
"+Bookmark.class.getName
()+" bm WHERE bm.userKeys = :userKey");
query.setParameter("userKey", user.getKey());
List<Bookmark> bookmarks = query.getResultList();
List<Book> books = new ArrayList<Book>();
for (Bookmark bookmark : bookmarks) {
Book book = bookmark.getBook();
book.getPage();
books.add(book);
}
return books;
}
}
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