ftUnknown
ftUnknown = 0
Example
function HasKnownFieldType(Field: TField): Boolean;
begin
Result := Field.DataType <> ftUnknown;
end;
Usage
ftUnknown identifies the zero sentinel for an unknown or unresolved field type and has no default Velox field class.
Additional Technical Info
ftUnknown is ordinal 0 of TFieldType. It means the type is unknown or undetermined. The installed RTL has no default field class for it.
Treat it as unresolved metadata, not a string, Variant or safe generic value. It can indicate an uninitialised parameter, unsupported provider type or incomplete schema discovery. Stop type-dependent conversion and obtain the real metadata or handle the value through an explicitly supported provider path.
Do not persist ordinal zero as a substitute for a real external type or silently coerce unknown values; that can hide schema drift and data loss.
The example only inspects metadata and was source-reviewed; no provider discovery, dataset, database, runtime or image test ran.
External references
- Embarcadero
TFieldType. - Free Pascal
TFieldTypecompatibility reference.