RAD Studio VCL Reference
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Determines whether the value of the field is calculated by the OnCalcFields event handler of its dataset.
property Calculated: Boolean;
__property Boolean Calculated;
Use Calculated to determine if the field is a calculated field. When Calculated is true and the OnCalcFields event occurs, the OnCalcFields event handler updates the value of the field. The default value is false.
The value of a Calculated field is not stored in or retrieved from the physical tables underlying a dataset. Instead, calculated fields are calculated for each record in the table by the dataset's OnCalcFields event handler, which typically uses expressions involving values from other fields in the record to generate a value for each calculated field.
For example, a dataset might have non-calculated fields for Quantity and UnitPrice, and a calculated field for ExtendedPrice, which would be calculated by multiplying the values of the Quantity and UnitPrice fields in an OnCalcFields event handler.
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