Welcome!

Java IoT Authors: Yeshim Deniz, Zakia Bouachraoui, Elizabeth White, Pat Romanski, Liz McMillan

Related Topics: Java IoT, Eclipse

Java IoT: Blog Feed Post

What's the Difference Between dataSetRow["FIELD"] and row["FIELD"]

Let me see if I can set the record straight

One of the most common questions for people that are new to BIRT is about how to ask data from the DataSet in the report.  The question is when building expressions should I use dataSetRow["FIELD"] or row["FIELD"]?

So let me see if I can set the record straight.  When data is acquired, it is acquired by a DataSet, so the following query in a JDBC DataSet will create a three field resultset:

select CITY, STATE, COUNTRY 
from CUSTOMERS



Any script or expressions written on the DataSet will be written to use the format

row["FIELD_NAME"];

So if we add a computed column to the DataSet called compCityState, the expression would look like this.

Once a computed column is created, you can reference that computed column using the same row syntax.  So in the OnFetch method you could add this message to log the value of the computed column.

Packages.java.lang.System.out.println(row["compCityState"]);


The other place that you can access variable on the DataSet is through ReportItem binding.  In most cases, this means Table Binding where you have attached a table to a DataSet.  In general, when you use BIRT you associate a Table with a DataSet.  We say that the Table is bound to the DataSet.

When a DataSet is dragged to the Layout editor, BIRT automatically does the data binding and creates a bound column for each field and computed column in the DataSet.  The following shows a table and its Binding.


You will notice that all of the expressions use the term dataSetRow, which means this value is pulled from the DataSet.  Now for the tricky bit, any field that is bound to a Table can be used in another table binding.  So if we wanted to create a field that has City, State and Country, we could either:
a) go back to the DataSet
b) add a new table binding

When you add a binding to a table you are brought to the expression builder.  In this first example, I am creating a table binding that gathers data straight from the DataSet.


Because I am referencing the DataSet directly the expression uses the dataSetRow syntax.

In the next example, I will use the previously established bindings to build the expression.  In the expression builder I will select Available Column Bindings and the Table and then select the fields.  You will also notice that the Table Binding has access to any of the previously bound fields and a special RowNumber field.

The important thing is that the syntax to access those values is to use row["FIELD_NAME"]


So the short answer is, dataSetRow syntax references the original values from the DataSet, whereas the row syntax references the bound column values.

Now for a quick test, this should be easy.

Imagine that I change the expression of the CITY expression to look like this, and all else remains the same.


If the values for the row are:
City: Kalamazoo
State: MI
Country: USA

What will a DataItem that is showing rowCityStateZip display?
What will a DataItem that is showing tablCityStateCountry display?

The answers will be after a short shameless promotion of my companies BIRT training program.  We have designed a modular training program that is focused on teaching you how BIRT works.  You can take one module or all of them.  The focus of our training is on how BIRT works, so that when you finish you really understand what is going on in the product.

Our training can be taken on-site, or through remote sessions of between two and four hours each.  We are also happy to work with your team to customize the training to match your companies needs.   If you are interested, please visit our web site and have a look.

Answers:
rowCityStateZip:        { Kalamazoo }, MI USA
tablCityStateCountry:  Kalamazoo, MI USA

Remember, dataSetRow syntax (as used in tablCityStateCountry) goes back to the original data.  Row syntax use the table binding.

Read the original blog entry...

More Stories By Jason Weathersby

Jason Weathersby is a member of the extended BIRT development team at Actuate Corporation and has backgrounds in both computer science and technical writing. He has many years experience in technical consulting, training, writing, and publishing about reporting, business intelligence tools, and database technologies.

IoT & Smart Cities Stories
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
Nicolas Fierro is CEO of MIMIR Blockchain Solutions. He is a programmer, technologist, and operations dev who has worked with Ethereum and blockchain since 2014. His knowledge in blockchain dates to when he performed dev ops services to the Ethereum Foundation as one the privileged few developers to work with the original core team in Switzerland.
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
Whenever a new technology hits the high points of hype, everyone starts talking about it like it will solve all their business problems. Blockchain is one of those technologies. According to Gartner's latest report on the hype cycle of emerging technologies, blockchain has just passed the peak of their hype cycle curve. If you read the news articles about it, one would think it has taken over the technology world. No disruptive technology is without its challenges and potential impediments t...
If a machine can invent, does this mean the end of the patent system as we know it? The patent system, both in the US and Europe, allows companies to protect their inventions and helps foster innovation. However, Artificial Intelligence (AI) could be set to disrupt the patent system as we know it. This talk will examine how AI may change the patent landscape in the years to come. Furthermore, ways in which companies can best protect their AI related inventions will be examined from both a US and...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of San...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...