Hibernate since 2001. Is time for Cyberpunk 2020?

Hibernate was started in 2001 as an alternative to using EJB2-style entity beans. But today EJB is forgotten and everybody wants to make modern software with Java 8 features. Hibernate is de facto industry standard. But what if it isn’t universal solution for all systems? How to do better declarative or functional querying?

Let’s put aside classic Object-Relational Mapping and look at other, modern capabilities to know pros and cons of DSLs, lambdas and streams usage with relational databases.

Transcript

1. HIBERNATE SINCE 2001. IS TIME FOR CYBERPUNK 2020? TOMASZ SKOWROŃSKI JDD, Kraków 10.10.2016
2. DATABASE
3. 1960s CODASYL, network model
4. 1960s IMS, hierarchical model
5. 1962 The SABRE system
6. 1968 Planet of the Apes
7. RELATIONAL DATABASES 1970s Ingres and IBM System R 1980s SQL became the standard
8. SQL HISTORY SQL-86 1st formalized by ANSI SQL-92 3rd revision of the SQL SQL:2011 last SQL standard
9. VANILLA JAVA
10. JDBC Connection dbConnection = null; PreparedStatement preparedStatement = null; String sql = "SELECT USER_ID, USERNAME FROM DBUSER WHERE USER_ID = ?"; // more SQL here List<User> result = new LinkedList<User> (); try { dbConnection = getDBConnection(); preparedStatement = dbConnection.prepareStatement(sql); preparedStatement.setInt(1, userId); // more parameters here ResultSet rs = preparedStatement.executeQuery(); while (rs.next()) { result.add(new User( rs.getLong("USER_ID"), rs.getString("USERNAME") // more columns here )); } return result; } catch (SQLException e) { throw new IllegalStateException(e); } finally { if (preparedStatement != null) { preparedStatement.close(); } if (dbConnection != null) { dbConnection.close(); } }
11. JDBC IN JAVA 7/8 String sql = "select actor_id, concat(first_name, ' ', last_name) as fullname from sakila.actor where lcase(first_name) like lcase(?)"; // more SQL here List <ActorFullName> result = new LinkedList<> (); try (Connection c = dataSource.getConnection()) { try (PreparedStatement stmt = c.prepareStatement(sql)) { stmt.setString(1, "%" + text + "%"); // more parameters here try (ResultSet rs = stmt.executeQuery()) { while (rs.next()) { result.add(new ActorFullName( rs.getLong("actor_id"), rs.getString("fullname") // more columns here )); } return result; } } } catch (SQLException e) { throw new IllegalStateException(e); } // try-with-resources close all
12. SPRING JDBC TEMPLATE + GROOVY String sql = """ select actor_id, concat(first_name, ' ', last_name) as fullname from sakila.actor where lcase(first_name) like lcase(?) """ // more SQL here return jdbcTemplate.query(sql, ["%Karl%"] as Object[], // more parameters here { ResultSet rs, int rowNum -> new ActorFullName( rs.getLong("actor_id"), rs.getString("fullname") ) // more columns here } as RowMapper)
13. HIBERNATE
14. 2001: A HIBERNATE ODYSSEY 2001 v0.8 alternative for EJB2-style 2003 v2 HQL, criteria 2006 v3.2 JPA 1.0 2010 v3.5 JPA 2.0, typed criteria 2013 v4.3.0 JPA 2.1 2014 Java 8 2015 v5 hibernate with Java 8 support
15. HIBERNATE AND JAVA 8 Java time (hibernate-java8) merged into core Optional<Book> book = session.byId(Book.class).loadOptional(id); Stream<Book> books = session.createQuery( "SELECT b FROM Book b", Book.class).stream();
16. XML OR ANNOTATIONS? @Entity public class Contact { @Id private long id; /* ... */ }
17. ANNOTATIONS? @Entity @Table(name = "CONTACTS") @NamedQueries({ @NamedQuery(name = "@HQL_GET_ALL_CONTACT", query = "from Contact") }) @NamedNativeQueries({ @NamedNativeQuery(name = "@SQL_GET_ALL_CONTACT", query = "select emp_id, contact_line1, city, zip from Contacts") }) public class Contact { @Id @Column(name = "emp_id", unique = true, nullable = false) @GeneratedValue(generator = "gen") @GenericGenerator(name = "gen", strategy = "foreign", parameters = { @Parameter(name = "property", value = "employee") }) private long id; @OneToMany(cascade = CascadeType.ALL) @JoinTable(name = "CONTACT_PHONE", joinColumns = { @JoinColumn(name = "CONTACT_ID") }, inverseJoinColumns = { @JoinColumn(name = "PHONE_ID") }) public Set<Phone> getContactPhoneNumbers() { return this.contactPhoneNumbers; } /* … */ }
18. STRING-DRIVEN DEVELOPMENT
19. STRING-DRIVEN DEVELOPMENT @NamedNativeQuery(name = "nativeSQL", query = "SELECT emp1.emp_id, emp1.name, emp1.manager_id," + " emp1.dept_id, emp1.address_id" + " FROM EMP emp1, EMP emp2" + " WHERE ((emp2.EMP_ID = ?) AND (emp2.EMP_ID = emp1.MANAGER_ID))", resultClass = Professor.class)
20. USER DEFINED LANGUAGE INJECTION IntelliJ IDEA
21. CRITERIA List<Cat> cats = sess.createCriteria(Cat.class) .add(Property.forName("name").like("F%")) .addOrder(Property.forName("name").asc()) .setMaxResults(50) .list();
22. TYPESAFE CRITERIA CriteriaBuilder builder = entityManager.getCriteriaBuilder(); CriteriaQuery<String> criteria = builder.createQuery(String.class); Root<Person> root = criteria.from(Person.class); criteria.select(root.get(Person_.nickName)); criteria.where(builder.equal(root.get(Person_.name), "John Doe")); List<String> names = entityManager.createQuery(criteria).getResultList();
23. MYBATIS new SQL().INSERT_INTO("PERSON") .VALUES("ID, FIRST_NAME", "#{id}, #{firstName}"); new SQL() { SELECT("P.ID, P.USERNAME, P.PASSWORD, P.FULL_NAME"); SELECT("P.LAST_NAME, P.CREATED_ON, P.UPDATED_ON"); FROM("PERSON P"); FROM("ACCOUNT A"); INNER_JOIN("DEPARTMENT D on D.ID = P.DEPARTMENT_ID"); INNER_JOIN("COMPANY C on D.COMPANY_ID = C.ID"); WHERE("P.ID = A.ID"); WHERE("P.FIRST_NAME like ?"); OR(); WHERE("P.LAST_NAME like ?"); GROUP_BY("P.ID"); HAVING("P.LAST_NAME like ?"); };
24. SPRING DATA JPA
25. QUERIES FROM METHOD NAMES extends Repository<T, ID> extends CrudRepository<T, ID> User findOneByDeletedIsFalseAndLogin(String login); User findOneByDeletedIsFalseAndEmail(String email); User findOneByDeletedIsFalseAndActivationKey(String key); List<Todo> findByDescriptionContainsOrTitleContainsAllIgnoreCase( String descriptionPart, String titlePart); List<InstanceConfig> findByConfigAppIdAndConfigClusterNameAndConfigNamespaceNameAn dDataChangeLastModifiedTimeAfter( String appId, String clusterName, String namespaceName, Date validDate);
26. SPECIFICATIONS List<Customer> customers = customerRepository.findAll( where(isLongTermCustomer()).or(hasSalesOfMoreThan(amount))); public class CustomerSpecs { public static Specification<Customer> isLongTermCustomer() { return (root, query, builder) -> { LocalDate date = LocalDate.now().minusYears(2); return builder.lessThan(root.get(_Customer.createdAt), date); }; } public static Specification<Customer> hasSalesOfMoreThan(BigDecimal amount) { return (root, query, builder) -> { return builder.greaterThan((root.get(_Customer.sales), amount); }; } // more specifications here }
27. MEANWHILE, SOMEWHERE IN THE WORLD
28. .NET LINQ Language Integrated Query Northwnd nw = new Northwnd(@"northwnd.mdf"); var companyNameQuery = from cust in nw.Customers where cust.City == "London" select cust.CompanyName;
29. RUBY ON RAILS Active Records users = User .where(name: 'David', occupation: 'Code Artist') .order(created_at: :desc)
30. CLOJURE KORMA (select user (with address) (fields :firstName) (where {:email "korma@sqlkorma.com"}))
31. SCALA SLICK for { c <- coffees if c.price > 9.0 s <- c.supplier } yield (c.name, s.name)
32. CYBERPUNK
33. JINQ Java INtegrated Query
34. QUERYLL 2006 - 2010 PhD research at EPFL university, Lausanne, Switzerland
35. JINQ 1.0 2014 Java 8 streams.streamAll(em, City.class) .filter(c -> c.getPopulation() > 25_000_000) .map(c -> c.getName()) .collect(toList()); streams.streamAll(em, City.class) .where(c -> c.getPopulation() > 25_000_000) .select(c -> c.getName()) .toList(); SELECT C.Name FROM City C WHERE C.Population > 25000000
36. JINQ
37. JINQ
38. JINQ
39. JINQ
40. JINQ
41. JINQ SELECT C.Name FROM City C WHERE C.Population > 25000000
42. HOW IT WORKS? no APT, no DB schema
43. no loops no type casting modify local variables locally read but not modify non-local variables
44. RESULT HANDLING entities, generic tuples, custom tuples
46. LIMITS only selects only known side-effects methods
47. String equals(), compareTo() BigDecimal, BigInteger, Integer, int, Double, double, Long, long ==, <, <=, >, >=, !=, +, -, *, / Float, float ==, <, <=, >, >=, !=, +, -, *, / Boolean, boolean !, &&, ||, == byte[] java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp, java.util.Calendar equals(), before(), after() enums ==, != entities ==, != java.util.Collection contains(), JPQL.isIn() AttributeConverter types equals(), ==, !=
48. TRANSLATABLE streams.setHint("exceptionOnTranslationFail", true);
49. MORE HINTS "useCaching" (default true) "queryLogger" "automaticPageSize"
50. QUERYDSL domain specific language
51. DATA/MODEL TYPE JPA JDO SQL collections Lucene Hibernate Search MongoDB
52. TYPES POPULARITY
53. MAVEN/GRADLE CONFIGURATION querydsl-jpa querydsl-apt
54. COMPILE Java Annotation Processing Tool
55. SIMPLE QUERYING QUser user = QUser.user; User u = queryFactory.selectFrom(user) .where(user.login.eq("David")) .fetchOne();
56. ORDERING AND GROUPING NumberPath<Long> count = Expressions.numberPath(Long.class, "c"); List<Tuple> userTitles = queryFactory .select(blogPost.title, blogPost.id.count().as(count)) .from(blogPost) .groupBy(blogPost.title) .orderBy(count.desc()) .fetch();
57. JOINS QBlogPost blogPost = QBlogPost.blogPost; List<User> users = queryFactory.selectFrom(user) .innerJoin(user.blogPosts, blogPost) .on(blogPost.title.eq("About me")) .fetch();
58. SUBQUERIES List<User> users = queryFactory.selectFrom(user) .where(user.id.in( JPAExpressions.select(blogPost.user.id) .from(blogPost) .where(blogPost.title.eq("About me")))) .fetch();
59. MODIFYING QUERIES queryFactory.update(user) .where(user.login.eq("Ash")) .set(user.login, "Ash2") .set(user.disabled, true) .execute();
60. RESULT HANDLING entities, collections, Groups non generic typesafe tuples constructor/accesors/fields projections Tuple result = query.select(actor.firstName, actor.lastName).from(actor).fetchOne(); String lastName = row.get(1, String.class); String firstName = row.get(actor.firstName);
61. JPA 2 CRITERIA VS QUERYDSL Query for single men and women as an cartesian
62. JPA 2 CRITERIA CriteriaQuery query = builder.createQuery(); Root<Person> men = query.from(Person.class); Root<Person> women = query.from(Person.class); Predicate menRestriction = builder.and( builder.equal(men.get(Person_.gender), Gender.MALE), builder.equal(men.get(Person_.relationshipStatus), RelationshipStatus.SINGLE)); Predicate womenRestriction = builder.and( builder.equal(women.get(Person_.gender), Gender.FEMALE), builder.equal(women.get(Person_.relationshipStatus), RelationshipStatus.SINGLE)); query.where(builder.and(menRestriction, womenRestriction));
63. QUERYDSL JPAQuery query = new JPAQuery(em); QPerson men = new QPerson("men"); QPerson women = new QPerson("women"); query.from(men, women).where( men.gender.eq(Gender.MALE), men.relationshipStatus.eq(RelationshipStatus.SINGLE), women.gender.eq(Gender.FEMALE), women.relationshipStatus.eq(RelationshipStatus.SINGLE));
64. SPRING DATA WITH QUERYDSL extends QueryDslPredicateExecutor long count(Predicate predicate); boolean exists(Predicate predicate); Iterable<T> findAll(Predicate predicate); T findOne(Predicate predicate); QTodo todo = QTodo.todo; repository.findAll(todo.group.eq(group) .and(todo.done.eq(false)));
65. JOOQ Java Object Oriented Querying
66. DATA MODEL code generation from DB schema from JPA entities without code generation
67. create.select(AUTHOR.FIRST_NAME, AUTHOR.LAST_NAME, count()) .from(AUTHOR) .join(BOOK).on(AUTHOR.ID.equal(BOOK.AUTHOR_ID)) .where(BOOK.LANGUAGE.eq("DE")) .and(BOOK.PUBLISHED.gt(date("2008-01-01"))) .groupBy(AUTHOR.FIRST_NAME, AUTHOR.LAST_NAME) .having(count().gt(5)) .orderBy(AUTHOR.LAST_NAME.asc().nullsFirst()) .limit(2) .offset(1)
68. ARTEFACTS schema metamodel (active) records POJOs, immutable POJOs, fluent setters JPA annotations, validation annotations DAOs, Spring annotations stored procedures
69. RESULT HANDLING generic tuples, collections RecordHandler, RecordMapper POJOs fetchLazy/stream
70. RECORDS strongly typed weakly typed BookRecord book = create.selectFrom(BOOK).fetchOne(); String title = book.getTitle()); Record record = create.select().from(BOOK) .join(AUTHOR).on(BOOK.AUTHOR_ID).fetchOne(); BookRecord book = record.into(BOOK); AuthorRecord author = record.into(AUTHOR);
71. TIPS IDE static imports for org.jooq.impl.DSL.* Spring Boot jOOQ feature MockDataProvider https://blog.jooq.org
72. CYBERPUNK - WHEN?
73. WHEN DATABASE FIRST data driven system more relational than hierarchical data model several applications access the same database
74. WHEN TYPESAFE QUERIES more complex querying than CRUD Command Query Responsibility Segregation SQL code in Java code
75. OR AS CYBERWARE as a SQL executor as a SQL builder as Active Records as CRUD with Hibernate, Spring Data...
76. ★ POPULARITY 392 jinq 583 speedment 990 querydsl 1354 jooq 2051 hibernate-orm stars on Github before 10.10.2016
77. OTHER CYBORGS speedment javalite ebean-orm jdbi
78. THANK YOU @tsskowronski
79. LINKS PHOTOS JinQ http://www.jinq.org/docs/queries.html http://www.slideshare.net/Strannik_2013/java-8-in-actionjinq#19 http://blog.jooq.org/2016/04/19/jooq-tuesdays-ming-yee-iu-gives-insight-into-language-integrated- querying http://infoscience.epfl.ch/record/153803/files/EPFL_TH4913.pdf Querydsl http://www.querydsl.com/static/querydsl/4.1.3/reference/html_single http://blog.mysema.com/search/label/querydsl jOOQ http://www.jooq.org/doc/latest/manual-single-page http://blog.jooq.org Metropolis 2001: A Space Odyssey Alien Blade Runner THX 1138