c# et al: May 2007

Thursday, May 24, 2007

Java Persistence API v1.0 (JPA)

http://www.cornerstone.se/expertzone/dev07/sessions_java.aspx

Declarative mappingFramework APIQuery LanguageTransaction Support
Entiteter: skall vara rena
ORM: Håller det hela i synk
Tjänster

Transparent Persitance

JPA 1.0 Declarative Object Relational Mapping
1. Classes are mapped to tables
2. Fields are mapped to columns
3. All types of relationships are supported
4. Support for embedded objects
5. Use either annotation or deployement descriptors

Laxy loading potentiellt problem med många sm@a
Eager loading kan ge stora SQL statements
Guideline Use laxy on relations and "fetch join" on queries
(Select * from Employee e LEFT JOIN FETCH e. phoneNumbers WHERE )

Contructor expressions in queries

Buld update delete

Valideringar - Lifecycle Callback