Posted 9:53 AM, 16 July 2009 by tcains
Excerpt from Professional SQL Server 2005 Reporting Services
The charting capabilities in SQL Server Reporting Services are quite impressive and as easy to use as those in Excel or Access, and, in many ways, they are more powerful. The charting components are based on Dundas Charts, developed by Dundas Software. Dundas provides a suite of ASP.NET charting components that have been available for .NET developers for several years. A chart item is based on a data set just like any data range and can use groups, query parameters, and filters in much the same way as a table, list, or matrix.
So, why use a chart to present data? After all, isn't a chart simply a graphical representation of a group of numbers? Wouldn't rows and columns of values be just as effective? To fully understand the impact and perhaps the importance of presenting information graphically, it's important to understand the needs and objective of the report reader and how the information will be used. For now, just consider some basic observations about report usage and the people who read these reports.
Analyzing information is usually a process rather than a single event. Regardless of the type of business or industry, users typically approach business information in stages. First it's important to consider the different roles of users in order to understand their respective stages of information discovery. Some may have a specific task they perform and the information they use will be focused on that task. Other users may be leaders and decision makers in various capacities, whose objectives are more broad and complex.
Consider the CEO whose first objective is often to find out whether there are any disasters to address. This executive isn't concerned with specific details or even short-term trends but in getting a meter reading on the business. After the CEO learns that there are no fires to put out, the next objective is to get a broad view of sales and productivity trends for different areas of the business. Typically, one of the most important questions addressed by effective business reporting solutions is How are we doing? Depending on the size and type of business, a high-level leader may also be interested in understanding some of the lower-level details regarding operations, production, sales, and other business specifics. Executives typically benefit from dashboard-type reports that provide high-level status information they use to take periodic business meter readings. Executives also need access to more detailed information to be used for occasional follow-up but will usually get their information from others.
Contrast the perspective of the CEO with the operational business leaders: the sales manager, marketing director, or production manager. These people need to have their finger on the pulse of specific business areas. They will be concerned with short- and long-term trends in their respective areas of responsibility. Questions to be answered for operational leaders might be What products or campaigns are successful and which are not? and Who are my top (and bottom) producers? Unlike the CEO, these individuals must be connected with every aspect of their microorganization and must be armed with detailed, accurate information so that they can make proactive decisions.
Consider that some users may need to have information spoon-fed to them in a specific format, while others may want to explore data, pivoting, sorting, and grouping it themselves.
Chart Types
Some of the more common chart types (like Column, Bar, Line, and Area) can be used for different views of the same data. Pie and doughnut charts present a more simplified view and work well with fewer dimensions. Other charts are more specialized and may be appropriate for multi-value data points, range values, and variances.
When a report is viewed, the chart output is rendered to a bitmap and streamed to a PNG-type image. This image is then linked or embedded in the report. There are nine general chart types available, and these are described in the following table.
Tags:
