Adds new field expression to the dataset.
function AddFieldExpression(const FieldName: string; const Expression: string; StrictReferences: boolean = False): TFieldExpression; overload;
The method adds new field expression to the dataset. The expression has to be specified in the string format using rules described in the article. To delete the field expression, TCustomEntityDataSet.DeleteFieldExpression method is used. To clear all dataset field expressions, the TCustomEntityDataSet.ClearFieldExpressions method is used.