Calculated fields can be used to create new values that do not exist in the data source. For example, a calculated field can represent a new value, a constant, an expression value, user defined function or even a report parameter, or an existing field that is converted to a different datatype.
You specify a calculated field manually by creating an expression. The Edit Calculated Fields dialog is available in the property grid of our DataSource components:
by clicking on the ellipsis of the CalculatedFields property.
The dialog accepts Name, DataType and Expression.
To edit a Calculated Field, click in the inline editors directly
To delete a Calculated Field, use the Delete Button
Names must be unique in the datasource and the expression for a calculated field cannot contain aggregates, RowNumber or ColumnNumber global functions.