Introduction to mybatis

Introduction to iBatis (MyBatis), An alternative to Hibernate and JDBC

I started to write a new article series about
iBatis/MyBatis. This is the first article and it will walk you through what isiBatis/MyBatisand
why you should use it.



For those who does not know
iBatis/MyBatis yet, it is a persistence framework – an alternative to JDBC andHibernate, available for Java and .NET platforms. I’ve been working
with it for almost two year, and I am enjoying it!
The fisrt thin you may notice in thisand following articles about iBatis/MyBatis is that I am using iBatisand Mybatis terms. Why? Until June 2010, iBatis was under Apachelicense and since then, the framework founders decided to
move it toGoogle Code and they renamed it to MyBatis. The framework is still thesame though, only has a different name now.
I gathered some resources, so I am just going to quote them:

What is MyBatis/iBatis?

The MyBatis data mapperframework makes it easier to use a relational database withobject-oriented applications. MyBatis couples objects with storedprocedures or SQL statements using a XML descriptor. Simplicity is thebiggest advantage of the MyBatis data
mapper over object relationalmapping tools.

To use the MyBatis data mapper, you rely on your own objects, XML, andSQL. There is little to learn that you don’t already know. With theMyBatis Data Mapper, you have the full power of both SQL and storedprocedures at your fingertips.

(www.mybatis.org)





iBATIS is based on the ideathat there is value in relational databases and SQL, and that it is agood idea to embrace the industrywide investment in SQL. We haveexperiences whereby the database and even the SQL itself have outlivedthe application source code,
and even multiple versions of the sourcecode. In some cases we have seen that an application was rewritten in adifferent language, but the SQL and database remained largely unchanged.

It is for such reasons that iBATIS does not attempt to hide SQL oravoid SQL. It is a persistence layer framework that instead embracesSQL by making it easier to work with and easier to integrate intomodern object-oriented software. These days, there are
rumors thatdatabases and SQL threaten our object models, but that does not have tobe the case. iBATIS can help to ensure that it is not.

(iBatis in Action book)

So…

What is iBatis ?

A JDBC Framework
Developers write SQL, iBATIS executes it using JDBC.
No more try/catch/finally/try/catch.
An SQL Mapper
Automatically maps object properties to prepared statement parameters.
Automatically maps result sets to objects.
Support for getting rid of N+1 queries.
A Transaction Manager
iBATIS will provide transaction management for database operations if no other transaction manager is available.
iBATIS will use external transaction management (Spring, EJB CMT, etc.) if available.
Great integration with Spring, but can also be used without Spring (the Spring folks were early supporters of iBATIS).

What isn’t iBATIS ?

An ORM
Does not generate SQL
Does not have a proprietary query language
Does not know about object identity
Does not transparently persist objects
Does not build an object cache

Essentially, iBatis is a very lightweight persistence solution thatgives you most of the semantics of an O/R Mapping toolkit, without allthe drama. In other words ,iBATIS strives to ease the development ofdata-driven applications by abstracting the low-level
details involvedin database communication (loading a database driver, obtaining andmanaging connections, managing transaction semantics, etc.), as well asproviding higher-level ORM capabilities (automated and configurablemapping of objects to SQL calls, data
type conversion management,support for static queries as well as dynamic queries based upon anobject’s state, mapping of complex joins to complex object graphs,etc.). iBATIS simply maps JavaBeans to SQL statements using a verysimple XML descriptor. Simplicity
is the key advantage of iBATIS overother frameworks and object relational mapping tools.(http://www.developersbook.com )

Who is using iBatis/MyBatis?

See the list in this link: http://www.apachebookstore.com/confluence/oss/pages/viewpage.action?pageId=25 I think the biggest case is
MySpace, with millions of users. Very nice!
This was just an introduction, so in next articles I will show how to create an application using iBatis/Mybatis – step-by-step.
Enjoy!