ActiveJDBC官方说明手册.pdf

ActiveJDBC == ActiveRecord for Java By Igor Polevoy August 2010 Who the heck is Igor Polevoy and why should we trust him • Developer like you • Architect • Teach Java/Rails at DePaul IPD • Battle-beaten on IT projects • Currently hacking away at Groupon, Chicago ..but why • Hibernate • JDO • JPA • iBatis • Castor • Torque • JPersist • …20 more Dissatisfaction • Hibernate: very powerful, but complicated, hard to setup, people have theories how it works, feels like a straight jacket, hard to learn • JPA – different configuration on every platform, not as feature reach as Hibernate, feels like a black box. • Most of all: getters/setters • Not OO! ActiveRecord just feels right • DHH is a great API designer • AR simple to use, yet provides a level of sophistication • Does not try to solve every problem under sun, but covers 80% of what you need; you can get your work done faster…much faster! • Complicated DB schemas ==usually== wrong design Who are parents of invention If necessity is a mother then… laziness is its father! ActiveJDBC Design principles • Should infer metadata from DB • Should be very easy to work with • Should reduce amount of code to a minimum • No configuration, just conventions • Conventions are overridable in code • No need to learn another language • No need to learn another QL ­ SQL is sufficient • Code must be lightweight and intuitive, should read like English • No sessions, no attaching, re­attaching • No persistence managers. • No classes outside your own models. • Models are lightweight, no transient fields • No proxying. What you write is what you get (WYWIWYG