This document provides an overview of nHibernate querying. It discusses how nHibernate works utilizing sessions to manipulate VOs. It also covers the criteria API, HQL, basic queries, restrictions using criteria, string matching, dynamic queries, subqueries, and using dynamic instantiation. References for further information on HQL and NHibernate in Action are provided.

1. nHibernate QueryAlbert Kuo

2. How nHibernation work?nHibernateQuerybasic queryRestrictionString matcherDynamic queriesSubqueriesUsing Dynamic InstitationAgenda2

3. How nHibernation work?Utilize session to manipulate VOsCriteriaSessiontablesVOsVOsVOsConfigurationSessionFactoryVOs3

4. How nHibernation work? – cont.createupdate4

5. How nHibernation work? – cont.deletefind5

6. nHibernate QueryCriteria APIHibernate Query LanguageObject oriented queryingIncrease compile-time syntax-checkingEasy to writeHard to readString-based queryingObject-Oriented SQLSimilar to SQLSpeak in terms of objectsCase sensitiveVery flexibleZero compile-time syntax-checking6

7. Using the ICriteriainterface:ICriteriacriteria = session.CreateCriteria(typeof(Cases));Generate SQL statement:select cases0_.caseId as caseId0_, cases0_.caseDesc as caseDesc0_, cases0_.caseTime as caseTime0_, cases0_.caseType as caseType0_, cases0_.caseAddr as caseAddr0_, cases0_.reporterStaff as reporter6_0_, cases0_.reporterPhone as reporter7_0_, cases0_.reporterAddr as reporter8_0_, cases0_.receiverStaff as receiver9_0_, cases0_.receiveTime as receive10_0_, cases0_.caseState as caseState0_, cases0_.updtDate as updtDate0_, cases0_.county as county0_, cases0_.town as town0_, cases0_.caseClass as caseClass0_ from Cases cases0_nHibernate Query – basic query7

8. You usually don’t want to retrieve all instances of a class when you run a query. Instead, you want to express some constraints on the property values of your objects, so only a subset of objects is retrieved. This is called restriction.nHibernate Query – Restriction8

9. The like operator allows wildcard searches, where the wildcard symbols are % and _nHibernate Query – String matcher9

10. It’s common for queries to be built programmatically by combining several optional query criteria depending on user input.nHibernate Query – Dynamic queries10

11. 11

12. nHibernate Query – Subqueries12

13. If you find working with arrays of values a little cumbersome, NHibernate let’s you use dynamic instantiation and define a class to represent each row of results. You can do this using the HQL select new construct:The custom ItemRow class doesn’t have to be a persistent class that has its own mapping file. But in order for NHibernate to “see” it, you need to import it usingnHibernate Query – Using Dynamic Institation13

14. Chapter 11. HQL: The Hibernate Query Languagehttps://www.hibernate.org/hib_docs/nhibernate/html/queryhql.htmlNHibernate in Actionhttp://www.manning.com/kuate/Reference14