Crystal Reports includes a number of summarizing options. A subtotal is the sum of all values from a single field, from all the records in a group. In a sales report, for example, if you subtotal the amount ordered by sales representative, Crystal Reports gathers all the records that belong to the sales representative and totals the amounts ordered from all the records.
When the program summarizes data, it sorts the data, breaks it into meaningful groups, and then summarizes the values in each group automatically.
Depending on the data type of the field that you plan to summarize, you can:
Sum the values in each group.
Count all the values or only those values that are distinct from one another.
Determine the maximum, minimum, average, or Nth largest value.
Calculate up to two kinds of standard deviations and variances.
Inserting Summary Fields
When you insert a summary in your report that contains one or more groups, you have a choice of where to place the field.
When you select the inserted summary field, you can see its full name in the Status bar at the bottom of the Design window.
The summary field automatically lines up with and attaches to the same guideline as the field it was based on.
You can also insert a simple text object as a label beside your summary field as an explanation to make it meaningful for the user. Adding a text object as an explanatory label in front of the summary or subtotal helps to further describe the context of the new summary or subtotal. For example, a subtotal that sums the sales of a particular region could read "Subtotal of Last Year’s Sales by Region."
You can insert summary information in either the Design or Preview tabs. The options available when inserting a summary field vary depending on the type of data you are summarizing.