Sometimes it is necessary to augment the data returned in a data group with additional fields, calculated on data in the data group or from elsewhere. Age is a good example as many data sources will hold the date of birth but you want your output to show the person's age. If that value is not available to you, use a Data Item to add the field.

You can also override a field that is returned from the data source by creating a data item with the same Id as the field. For example if you wanted to prefix a field with a label.

The following settings are available for each data item:

• Id - uniquely identifies the data item in the data group
• Name - a brief description which is used as the default label for the field
• Function - use the Function Builder to define the calculated value
• Field - optionally select a field from the data group that acts as the 'current value' when evaluating the function
• Format - whether the field is text, number, dateTime or boolean (yes/no)

If the data item's format is number or dateTime you may also specify the output format. The Output Format Helper will open automatically to assist in the format specification.