ireport generated report breaks

[kalyen kumar]

Hi,

I am new to iReport 3.5.0.
I created a sample report by connecting to my MS SQL SERVER DB.
But the problem is whenever there is change in column name of a table in my DB, the report breaks.

QUESTION: What should I do to decouple the report from my DB so that my DB changes wont break my report.

Thanks in advance,
Kalyen

[Martijn Verburg]

How/why does it break?

[Gerardo Tasistro]

Pass it a bean. Use beans as source rather than raw SQL. That will decouple your report logic from the data access logic.

[kalyen kumar]

So using using Hibernate in my application answers this question...?

Here is another discussion of my question

http://jasperforge.org/plugins/espforum/view.php?group_id=83&forumid=101&topicid=61624

[kalyen kumar]

Hi Martijn Verburg,

It breaks because when I run the report after changing the column name, it will throw an exception that the column name not found.

What I am talking about is a data abstration layer sits between the database and your reports....even if the database structure changes then instead of being required to change what could be hundreds or even thousands of reports throughout an organization, to accomodate the change you instead make the changes in this layer and those changes are automatically passed through to all the reports.

Thanks in advance,
Kalyen

[Martijn Verburg]

Yes, you should have a DAO layer of some sort that abstracts this out. Using Hibernate or a similar ORM mapping tool is probably recommended here.

[kalyen kumar]

Hi,

Thanks for your response.
So, if I use hibernate.......and I am directly accessing database without integrating the reporting tool with any application,
then how do I proceed...?

If I use the tool independently (tool interacting directly with database and creating reports) then how can I use hibernate here...?
I am confused.........

Thanks in advance
Kalyen

[Martijn Verburg]

Sorry I probably threw you a red herring with my comment. I'd go back to what Gerardo Tasistro said, you'l want to use beans or some other sort of abstraction layer (which could be hibernate or something like that). I suggest you google "Jasper Reports and data Beans" and see what you get..

[Gerardo Tasistro]

kalyen kumar wrote:

If I use the tool independently (tool interacting directly with database and creating reports) then how can I use hibernate here...?
I am confused.........

I've used iReports with Hibernate directly and I don't recommend it. It is a nice solution, but you don't break away completely form the issues you mention. Your report tool still remains coupled to your application because any change to the application's data model. I've moved to using a pure Java Bean solution. It is the responsibility of the application to create an array of such beans and pass it to the report. That way you have:

my.report.package.ReportBean  // which is the bean registered in the IReport tool and you can move it around all you want, it is also contained in its little small jar which you place in iReport's classpath

then you have

my.application.package.DataBean // which is the bean you use with Hibernate to retrieve and store you application data, some fields from DataBean correspond to some fields in ReportBean, 
// or maybe you have aggregate functions or joins with other beans.  That all depends on how you represent data on your application

Your application should have a way to convert a DataBean to a ReportBean in such a way to create:

List<ReportBean> reportList=buildMyReportData(...whatever parameters here...);

Then you fill the report with reportList using JasperFillManager.fillReport(...);

[kalyen kumar]

Hi Gerardo Tasistro,

A very nice response, I am very much happy with your answer.

Thanks a lot.

Is the following same as that you are talking about......?

http://ixfree.wordpress.com/2007/07/04/jasper-ireport/

Thanks in Advance,
Kalyen

[Gerardo Tasistro]

A bit like that. Although I omit the FactoryBean and just pass the data directly

Example from http://www.devdaily.com/java/jwarehouse/spring-framework-2.5.3/src/org/springframework/web/servlet/view/jasperreports/AbstractJasperReportsView.java.shtml

	protected JasperPrint fillReport(Map model) throws IllegalArgumentException, SQLException, JRException {
		// Determine main report.
		JasperReport report = getReport();
		if (report == null) {
			throw new IllegalStateException("No main report defined for 'fillReport' - " +
					"specify a 'url' on this view or override 'getReport()' or 'fillReport(Map)'");
		}

		// Determine JRDataSource for main report.
		JRDataSource jrDataSource = getReportData(model);
		if (jrDataSource != null) {
			// Use the JasperReports JRDataSource.
			if (logger.isDebugEnabled()) {
				logger.debug("Filling report with JRDataSource [" + jrDataSource + "].");
			}
			return JasperFillManager.fillReport(report, model, jrDataSource);
		}

		else {
			if (this.jdbcDataSource == null) {
				this.jdbcDataSource = (DataSource) CollectionUtils.findValueOfType(model.values(), DataSource.class);
			}

			if (this.jdbcDataSource != null) {
				// Use the JDBC DataSource.
				if (logger.isDebugEnabled()) {
					logger.debug("Filling report with JDBC DataSource [" + this.jdbcDataSource + "].");
				}
				Connection con = this.jdbcDataSource.getConnection();
				try {
					return JasperFillManager.fillReport(report, model, con);
				}
				finally {
					try {
						con.close();
					}
					catch (Throwable ex) {
						logger.debug("Could not close JDBC Connection", ex);
					}
				}
			}

			else {
				// Assume that the model contains parameters that identify
				// the source for report data (e.g. Hibernate or JPA queries).
				return JasperFillManager.fillReport(report, model);
			}
		}
	}


    

[kalyen kumar]

Hi,

Thanks a lot.
I will be starting implementing this with the guidance given by you.

I hope you will be in touch for further guidance, definitely not step by step (because you have already given it )
but if any road blocks I face or for gaining better understanding of things.

Thanks you all,
Kalyen