Summarizing data in portalsYou can summarize data that's in a related field displayed in a portal. For example, you can get the total of all related records, the smallest or largest related record, or find the standard deviation of all related records in your portal. The portal can contain records from a related table or from the same table, using a relationship defined from and to the current table (a self-join).
1. Create a summary field in the table that related records are being displayed from. (This is the table displayed in the Portal Setup dialog box.) See Defining summary fields for more information.Tip For a more complex summary of your data, use a calculation field to define a formula. See Defining calculation fields for more information.See Placing and removing fields on a layout for more information.