Grouping and Summarizing Data in a Report Template

 

Overview

Grouping organizes report data into sections based on a common field value, such as folder name or risk owner.

After groups are created, summary variables can calculate totals, counts, or other aggregated values within each group. Charts added to the Summary band can then display these summarized results visually.

 

Add a Group Band

• Open the report in Jaspersoft Studio.
• In the Outline panel, right-click the report name and select Create Group.
• Enter a Group Name
  • this typically matches the grouping field (e.g. Folder).
• Select Create Group from a report object.
• In the Report Objects list, select the grouping field and click Next.
  • e.g. folderName
• Select Add the Group Header and Add the Group Footer as needed, then click Finish.
• Drag the grouping field from the Fields panel into the new Group Header band.
• Add a Sort Field:
  • Right-click Sort Fields in the Outline panel
  • Select Create Sort Field
  • Choose the same field and click Finish.

Note: Without a matching Sort Field, risks from different groups may interleave in the dataset, causing the same group header to appear more than once. 

 

Add a Count or Sum Variable

• Drag the field to count or sum into the Group Footer or Summary band.
  • e.g. id for a risk count
• In the TextField Wizard, select the calculation type (Count, Sum, Average, etc.) and click Finish.
• A variable is created automatically in the Outline panel under Variables.
• Click the variable to review its properties.
  • For a per-group calculation, Reset type should be set to [Group] followed by the group name.
  • For a report-wide total, change Reset type to Report and place the variable in the Summary band.

Note: Variables are calculated as Jaspersoft Studio processes each record. Always place count or sum variables in a footer or summary band, never in the Detail band.

 

Add a Chart to the Summary Band

Charts must be placed in the Summary band, so all grouped data has been gathered before the chart renders.

• Confirm group variables and calculations are in place.
• From the Basic Elements panel, drag a Chart element into the Summary band.
• In the Chart Wizard, select the chart type (e.g. Bar Chart) and click Next.
• Configure the chart data:

    Series: Enter a label for the data series

    Value: Select the variable to plot (e.g. $V{FolderRiskCount})

    Category: Select the X-axis label field (e.g. $F{folderName})

    Increment on: Set to [Group] followed by the group name

• Click Finish, resize the chart element, and click Preview to verify the output.

 

Best Practices

• Always add a Sort Field alongside each Group band to prevent duplicate groups.
• Use Distinct Count when counting risks by a field that may contain repeated values for the same risk.
• Place charts and grand total variables in the Summary band, not in Group Footer bands.
• Handle null values in numeric calculations using: RD.FormatFtns.nullZero($F{fieldName})

 

Troubleshooting

• Groups repeat for the same value:
  • A Sort Field has not been added. Add one via right-click > Sort Fields > Create Sort Field.
• Count or sum displays NULL: Use: $V{MyVar} == null ? 0 : $V{MyVar}
• Chart does not reflect all data:
  • Confirm the chart is in the Summary band and the Increment on setting matches the correct group name.