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Monday, 29 April 2013

session.createSQLQuery()

Hibernate provides us with the option to fire explicit SQL queries. But with the presence of HQL and Criteria why would one want to do that ?

Thursday, 25 April 2013

Getting the total records while using pagination

We often have grids in our application where we need to show the results as pages. There is also often a row of text making the claim " Record  1 to 30 of 100". While the bounds of the result can be obtained easily as we know the limits to apply, it is getting the total record count that is interesting.

Tuesday, 16 April 2013

Select in Criteria using SQL

In an earlier post we saw how Criteria provided us with the ability to add restrictions in the where clause using pure SQL. The next question would then be if Criteria allows SQL in select clause ?

Saturday, 13 April 2013

Friday, 12 April 2013

The first CXF Service

In the previous post we saw how JAX-WS 's RI implementation could be used to build and interact with web services. I decided to work with one of the other implementations - Apache CXF. I decided to create and run a code first webservice using CXF implementation.

Tuesday, 9 April 2013

Criteria and Aggregation

We saw aggregate functions with HQL. Criteria too has methods that provide for using aggregate functions. Consider the below code that simply fetches the count of all rows.

Saturday, 6 April 2013

Setting schema information

In all my posts on JPA I have used a PostgreSQL database. The database is composed of multiple schemas (Unlike PostgreSQL, MySQL database supports only a single schema). So we need to specify to our application the schema being used. I did that by setting the schema attribute of the Table annotation.

Thursday, 4 April 2013

Learning web services

In the various programming environments supported by Java, I have found web-services to be the most difficult to penetrate (That and JNDI) . The thing is there are several web-service providers in the Java community. They all make various claims, add to already vague terminology and almost always leave a novice reader confused.
So when I got a chance to implement web services using Spring's web service framework, I was pleasantly surprised with the well explained Spring docs. And while learning some cool stuff, I also realized that Spring web services is quite different from some of the other implementations.
So when I got the chance today, I decided  to do some investigation on few of these frameworks. I have earlier blogged on how Spring allows us to expose our application as a web service
Spring's web service implementation is not related to JAX-WS. Spring's implementation as we saw, only supports contract first development. There are several advantages to the same. In the words of Spring web services creator Arjen Poutsma

Wednesday, 3 April 2013

criteria.setProjection()

In previous posts we have seen how to use the Criteria interface. We have also been using the setProjection method when needed to select properties or objects from the executed query.