Data.DB.TDataSet.Lookup
Delphi
function Lookup(const KeyFields: string; const KeyValues: Variant;
const ResultFields: string): Variant; virtual;
C++
virtual System::Variant __fastcall Lookup(const System::UnicodeString KeyFields, const System::Variant &KeyValues, const System::UnicodeString ResultFields);
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| function | public | Data.DB.pas Data.DB.hpp |
Data.DB | TDataSet |
Description
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.