Sometimes displaying a single value can be more meaningful than displaying the full list of records available in the database. For instance displaying the total revenue from the orders, instead of displaying every single order.
To aggregate a column into a single value, click on the column header, click and choose one of the available aggregate functions:
The list of available aggregate functions depends on the data type of the column. Sum and Average are only available for numeric data types; textual data types (text, e-mail, and phone number) only have available the Count function.
To calculate the total income that is recorded in the OrderItem entity:
After you use an Aggregate Function, a new column with the calculated value is added to the beginning of your table, separated from the rest of the columns by a vertical line. The output of the aggregate is only what appears on the left of the separator. The rest of the columns are still visible in the query for informative purposes only. You are not able to reference them when using the aggregate results.
Create a Calculated Column | Segment Identical Data into Groups