API:FireDAC.Comp.DataSet.TFDDataSet.Lookup
| [–] Properties | |
|---|---|
| Type: function | |
| Visibility: public | |
| Source: FireDAC.Comp.DataSet.pas FireDAC.Comp.DataSet.hpp
| |
| Unit: FireDAC.Comp.DataSet | |
| Parent: TFDDataSet | |
Delphi
function Lookup(const AKeyFields: string; const AKeyValues: Variant;
const AResultFields: string): Variant; override;
C++
virtual System::Variant __fastcall Lookup(const System::UnicodeString AKeyFields, const System::Variant &AKeyValues, const System::UnicodeString AResultFields);
Description
Implements a virtual method to retrieve field values from a record that matches specified search values.
FireDAC.Comp.DataSet.TFDDataSet.Lookup inherits from Data.DB.TDataSet.Lookup. All content below this line refers to Data.DB.TDataSet.Lookup.
Implements a virtual method to retrieve field values from a record that matches specified search values.
This function:
Checks whether the dataset is unidirectional, and if so, raises an EDatabaseError exception.
Returns a Variant with the value false, indicating that a matching record was not found.
Descendant classes that are not unidirectional override this method so that it locates the record where the fields identified by the comma-delimited string KeyFields have the values specified by the Variant or Variant array KeyValues. In classes that implement Lookup, it returns a Variant or Variant array that contains the value or values of the fields specified by the comma-delimited string ResultFields on the specified record.