ftReference

ftReference = 28

Example

function IsDatabaseReference(Field: TField): Boolean;
begin
  Result := Field.DataType = ftReference;
end;

Usage

ftReference identifies a database REF value exposed through a specialised nested-dataset reference field.

Additional Technical Info

ftReference is ordinal 28 of TFieldType. Delphi maps it to TReferenceField, a TDataSetField descendant with ReferenceTableName metadata and nested-dataset behavior.

It is a database object/reference concept, not a Pascal pointer, URL or foreign-key scalar. Identity, dereferencing, update behavior, dangling references and transaction visibility are provider/database contracts. Do not serialize an internal reference representation or assume it remains valid outside its session.

Use schema-supported identity values for cross-system mappings. Keep a Null reference distinct from a referenced row whose fields are Null.

The example only inspects metadata and was source-reviewed; no reference dereference, nested dataset, database, runtime or image test ran.

External references

• Embarcadero TFieldType and TReferenceField.
• Free Pascal TFieldType compatibility reference; REF support is provider-specific.

Created 2026-07-15